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Internat. J. Math. & Math. Sci.                                                                              405
VOL. 18 NO. 2 (1995) 405-410




                               THE UNITARY AMICABLE PAIRS TO I(P

                                               RUDOLPH M. NAJAR

                                          Department of Mathematics
                                      California State University, Fresno
                                            Fresno, CA 93740-0108

               (Received January 13, 1993 and in revised form March 19, 1994)




ABSTRACT: We present an exhaustive list of the 185 unitary amicable pairs whose smaller
number is less than 108 and a new unitary sociable set of four numbers.

KEY WORDS AND PHRASES. Unitary amicable pairs, unitary sociable sets.
1991 AMS SUBJECT CLASSIFICATION CODE. 11A25

        INTRODUCTION.
        A unitary amicable pair (UAP) is a pair of integers m, n such that

                                       6*(m) m + n t*(n)                                             (1.1)

where t* is the sum of unitary divisors function. In 1971, Hagis [4] published a table of UAP’s,
including the results of an exhaustive computer search for all pairs with smaller number less than 106.
There were thirty-two UAP’s in the table, none of which were simultaneously ordinary amicable pairs;
i.e., which were not square-free. The definitions of unitary amicable pairs and ordinary amicable pairs
overlap on square-free pairs. Hagis did not list Wall’s dissertation [7] which included several hundred
UAP’s. Since Hagis, several writers (see, for example [3] and [5]) have added to the known UAP’s.

        UNITARY AMICABLE PAIRS.
        The present search for UAP’s was conducted on a NeXT station using Mathematica.. Let

                                       s*(n)    t*(n) n.                                             (2.1)

The program searched for numbers k such that

                                       s*(s*(k))    k.                                               (2.2)

As part of a verification of the program, it initially picked out fixed points of the first ten iterates of s*,
thus finding the first four unitary perfect numbers.
        The search agreed with Hagis’s in finding the nineteen UAP’s less than 106 and the additional
four, pairs number 20, 24, 25, and 111 of this list, less than 108 that Hagis listed. The table follows.
406                                        R.M. NAJAR


Square free UAP’s are designated by an asterisk. The square-free UAP’s agree with the ordinary AP’s
found in te Riele [6]. Since Wall’s listing [7] was not in numerical order, this list was not compared
against his. Total running time is estimated to have exceeded I(X) hours.

                          TABLE OF UNITARY AMICABLE PAIRS TO l08

         114 2.3.19;                                126    2.3(2).7
2        1140 2(2).3.5.19;                          1260 2(2).3(2).5.7
3        18018 2.3(2).7.11.13;                      22302 2.3(3).7.59
4        32130-- 2.3(3).5.7.17;                     40446 2.3(3).7.107
5        44772 2(2).3.7.13.41;                      49308 2(2).3.7.587
6        56430 2.3(3).5.11.19;                      64530 2.3(3).5.239
7        67158 2.3(2).7.13.41;                      73962 2.3(2).7.587
8       *142310 2.5.7.19.107;                       168730 2.5.47.359
9.        180180 2(2).3(2).5.7.11.13;               223020 2(2).3(3).5.7.59
10.       197340 2(2).3.5.11.13.23;                 286500 2(2).3.5(3).191
11.      241110 2.3(3).5.19.47;                     242730 2.3(3).5.29.31
12.      296010 2.3(2).5.11.13.23;                  429750 2.3(2).5(3).191
13.      308220 2(2).3.5.11.467;                    365700 2(2).3.5(2).23.53
14.      462330 2.3(2).5.11.467;                    548550 2.3(2).5(2).23.53
15.      591030 2.3(3).5.11.199;                    618570 2.3(3).5.29.79
16.      669900 2(2).3.5(2).7.11.29;                827700 2(2).3.5(2).31.89
17.      671580 2(2).3(2).5.7.13.41;                739620 2(2).3(2).5.7.587
18.      785148 2(2).3.7.13.719;                    827652 2(2).3.7.59.167
19.      815100 2(2).3.5(2).11.13.19;               932100 2(2).3.5(2).13.239
20.       1004850 2.3(2).5(2).7.11.29;              1241550 2.3(2).5(2).31.89
21.     *1077890 2.5.11.41.239;                     1099390 2.5.17.29.223
22.       1080150 2.3.5(2).19.379;                  1291050 2.3(2).5(2).19.151
23.     * 1156870 2.5.11.13.809;                    1292570 2.5.19.6803
24.      1177722 2.3(2).7.13.719;                   1241478 2.3(2).7.59.167
25.       1222650 2.3(2).5(2).11.13.19;             1398150 2.3(2).5(2).13.239
26.       1281540 2(2).3.5.13.31.53;                1621500 2(2).3.5(3).23.47
27.      1475810 2.5.7.29.727;                      1669150 2.5(2).7.19.251
28.     * 1511930 2.5.7.21599;                      1598470 2.5.19.47.179
29.       1571388 2(2).3.7.13.1439;                 1654212 2(2).3.7.47.419
30.       1610700 2(2).3.5(2).7.13.59;              1883700 2(2).3(2).5(2).7.13.23
31.     *1669910 2.5.11.17.19.47;                   2062570 2.5.239.863
32.       1707720 2(3).3.5.7.19.107;                2024760 2(3).3.5.47.359
33.       1908420 2(2).3.5.17.1871;                 2135100 2(2).3.5(2).11.647
34.      1922310 2.3(2).5.13.31.53;                 2432250 2.3(2).5(3).23.47
35.      1997520 2(4).3.5.7.29.41;                  2115120 2(4).3.5.7.1259
36.     *2236570 2.5.7.89.359;                      2429030 2.5.23.59.179
37.      2357082 2.3(2).7.13.1439;                  2481318 2.3(2).7.47.419
38.     *2728726 2.7.11.13.29.47;                   3077354 2.7.19.23.503
39.      2862630- 2.3(3).5.17.1871;                 3202650 2.3(2).5(2).11.647
40.      3406116 2(2).3.7.23.41.43;                 3690204 2(2).3.7.197.223
41.      3482700 2(2).3.5(2).13.19.47;              3506100      2(2).3.5(2).13.29.31
42.      3951990 2.3(4).5.7.17.41;                  49748:8 2.3(4).7.41.107
UNITARY AMICABLE PAIRS                        407


43.     4198236 2(2).3.7.23.41.53;         4510884 2(2).3.7.83.647
44.    "4246130 2.5.7.60659;               4488910 2.5.23.29.673
45.     4439890 2.5.7(2).13.17.41;         5085710 2.5.7(2).97.107
46.    *4532710 2.5.7.13.17.293;           6135962 2.7.71.6173
47.     4918550 2.5(2).7.13.23.47;         5145322 2.7.13.17.1663
48.     5073570 2.3(3).5.19.23.43;         5570910 2.3(3).5.47.43
49.     5109174 2.3(2).7.23.41.43;         5535306 2.3(2).7.197.223
50.    *5123090 2.5.7.163.449;             5504110- 2.5.19.59.491
51.     5191290 2.3(4).5.13.17.29;         5967270 2.3(4).5.53.139
52.     5224050 2.3(2).5(2).13.19.47;      5259150 2.3(2).5(2).13.29.31
53.     5341620 2(2).3.5.127.701;          5441100 2(2).3.5(2).7.2591
54.    *5385310- 2.5.7.107.719;            5812130 2.5.17.179.191
55.     5431188 2(2).3.7.19.41.83;         5858412 2(2).3.7.97.719
56.     6297354 2.3(2).7.23.41.53;         6766326 2.3(2).7.83.647
57.     6381732 2(2).3.7.17.41.109;        6923868 2(2).3.7.139.593
58.     6433476 2(2).3.7.19.29.139;        7006524 2(2).3.7.239.349
59.     6940890 2.3(4).5.11.19.41;         7937190 2.3(4).5.41.239
60.    *6993610 2.5.13.23.2339;            7158710-- 2.5.13.53.1039
61.     7051590 2.3(3).5.7(2).13.41;       7766010 2.3(3).5.7(2).587
62.    *7288930 2.5.11.23.43.67;           8221598 2.7.11.197.271
63.     7929012 2(2).3.7.13.53.137;        8763468 2(2).3.7.104327
64.     8012430 2.3(2).5.127.701;          8161650 2.3(2).5(2).7.2591
65.     8095620 2(2).3.5.13.97.107;        9685500 2(2).3.5(3).11.587
66.     8146782 2.3(2).7.19.41.83;         8787618 2.3(2).7.97.719
67.     8194230 2.3(3).5.11.31.89;         9224010 2.3(3).5.127.269
68.     8235810 2.3(3).5.11.47.59;         9182430 2.3(3).5.71.479
69.     8537100 2(2).3.5(2).11.13.199;     8934900 2(2).3.5(2). 13.29.79
70.    *8619765 3.5.7.11.17.439;           9627915 3.5.11.23.43.59
71.    *8754130 2.5.7.11.11369;            10893230 2.5.757.1439
72.    *8826070 2.5.11.19.41.103;          10043690 2.5.31.179.181
73.     9057300 2(2).3.5(2).7.19.227;      9912300- 2(2).3.5(2).19.37.47
74.    *9478910 2.5.7.19.7127;             11049730 2.5.71.79.197
75.     9572598 2.3(2).7.17.41.109;        10385802 2.3(2).7.139.593
76.     9650214 2.3(2).7.19.29.139;        10509786 2.3(2).7.239.349
77.     9680310 2.3(4).5.17.19.37;         10511370 2.3(4).5.19.683
78.     9701076 2(2).3.7.11.10499;         10458924 2(2).3.7.89.1399
79.*    10254970 2.5.11.53.1759;           10273670 2.5.11.59.1583
80.     11777220 2(2).3(2).5.7.13.719;     12414780 2(2).3(2).5.7.59.167
81.     11893518 2.3(2).7.13.53.137;       13145202 2.3(2).7.104327
82.     12143430 2.3(2).5.13.97.107;       14528250 2.3(2).5(3).11.587
83.     12805650 2.3(2).5(2).11.13.199;    13402350 2.3(2).5(2).13.29.79
84.     12934680 2(3).3.5.11.41.239;       13192680 2(3).3.5.17.29.223
85.     13321490 2.5.7.13.14639;           16192750 2.5(3).7.19.487
86.     13585950 2.3(2).5(2).7.19.227;     14868450 2.3(2).5(2). 19.37.47
87.     13882440 2(3).3.5.11.13.809;       15510840 2(3).3.5.19.6803
88.     14257020 2(2).3.5.127.1871;        14496900 2(2).3.5(2).11.23.191
89.    *14426230 2.5.7.13.83.191;          18087818 2.7.31.71.587
90.     14551614 2.3(2).7.11.10499;        15688386    2.3(2).7.89.1399
408                                        R.M. NAJAR


91        14634270   2.3(4).5.7.29.89;            17247330   2.3(4).5.107.199
92.       16045722   2.3(3).7.11.17.227;          17048934   2.3(3).7.23.37.53
93.      16326090    2.3(3).5.11.23.239;          18510390   2.3(3).5.179.383
94.     *17041010    2.5.7.31.7853;               19150222   2.7.13.43.2447
95.     * 17257695   3.5.7.13.47.269;             17578785   3.5.7.23.29.251
96.       17278548   2(2).3.7.29.41.173;          17799852   2(2).3.7.29.7307
97.       17468730   2.3(3).5.23.29.97;           18093510   2.3(3).5.19.3527
98.       17709720   2(3).3.5.7.29.727;           20029800   2(3).3.5(2).7.19.251
99.       18143160   2(3).3.5.7.21599;            19181640   2(3).3.5.19.47.179
100.     20038920    2(3).3.5.11.17.19.47;        24750840   2(3).3.5.239.863
101.     21385530    2.3(2).5.127.1871;           21745350   2.3(2).5(2).11.23.191
102.    *21448630    2.5.7.131.2339;              23030090   2.5.19.53.2287
103.     21705684    2(2).3.7.11.13(2).139;       23990316   2(2).3.7.285599
104.     23570820    2(2).3(2).5.7.13.1439;       24813180   2(2).3(2).5.7.47.419
105.     24542700    2(2).3.5(2).7.13.29.31;      31367700 2(2).3(2).5(2).7.13.383
106.     25425876    2(2).3.7.19.89.179;          26414124 2(2).3.11.17.79.149
107.     25917822    2.3(2).7.29.41.173;          26699778 2.3(2).7.29.7307
108.     26355084    2(2).3.7.29.31.349;          27404916 2(2).3.7(2).11.19.223
109.     26791830    2.3(3).5.13.17.449;          30361770 2.3(3).5.139.809
110.     26838840    2(3).3.5.7.89.359;           29148360- 2(3).3.5.23.59.179
111.     27287260    2(2).5.7.11.13.29.47;        30773540 2(2).5.7.19.23.503
112.     29408130    2.3(3).5.17.43.149;          30467070 2.3(3).5.19.5939
113.     29656530    2.3(4).5.19.41.47;           29855790 2.3(4).5.29.31.41
114.    *30724694 2.7.11.13.103.149;              32174506 2.7.13.17.10399
115.     31035550 2.5(2).7.13.19.359;             31863650 2.5(2).7.13.47.149
116.     32558526 2.3(2).7.11.13(2).139;          35985474 2.3(2).7.285599
 117.    32744712 2(3).3.7.11.13.29.47;           36928248 2(3).3.7.19.23.503
 118.   *34256222 2.7.11.13.71.241;               35997346 2.7.11.23.10163
119.    *35361326 2.7.11.13.17.1039;              40117714 2.7.13.53.4159
 120.   *37784810 2.5.7.539783;                   39944086 2.7.13.41.53.101
 121.    38138310 2.3(3).5.7.17.1187;             48081978 2.3(3).7.131.971
 122.    38138814 2.3(2).7.19.89.179;             39621186 2.3(2).11.17.79.149
 123.    39532626 2.3(2).7.29.31.349;             41107374 2.3(2).7(2).11.19.223
 124.    40880532 2(2).3.7.11.151.293;            44920428 2(2).3.7.607.881
 125.    42740880 2(4).3.5.7.13.19.103;           52306800 2(4).3.5(2).7.13.479
 126.    43181292 2(2).3.7.11.17.2749;            51858708 2(2).3.11.131.2999
 127.    48339228 2(2).3.7.17.33851;              49154532 2(2).3.7.53.61.181
 128.    49117590 2.3(5).5.17.29.41;              50492970 2.3(5).5.11.1889
 129.    50953560 2(3).3.5.7.60659;               53866920 2(3).3.5.23.29.673
 130.    51091740- 2(2).3(2).5.7.23.41.43;        55353060 2(2).3(2).5.7.197.223
 131.    53278680 2(3).3.5.7(2).13.17.41;         61028520 2(3).3.5.7(2).97.107
 132.    54392520- 2(3).3.5.7.13.17.293;          73631544 2(3).3.7.71.6173
 133.    58062480 2(4).3.5.7.17.19.107;           68841840- 2(4).3.5.17.47.359
 134.    59022600 2(3).3.5(2).7.13.23.47;         61743864 2(3).3.7.13.17.1663
 135.    59037132 2(2).3.7.11.181.353;            64664628 2(2).3.7.251.3067
 136.    59604468 2(2).3.7.11.251.257;            65226252 2(2).3.7(3).13.23.53
 137.    60477900 2(2).3.5(2).7.31.929;           63323700 2(2).3.5(2).11.31.619
 138.    61320798 2.3(2).7.11.151.293;            67380642 2.3(2).7.607.881
UNITARY AMICABLE PAIRS                               409

 139.    61477080 2(3).3.5.7.163.449;        66049320  2(3).3.5.19.59.491
 140.    62973540 2(2).3(2).5.7.23.41.53;    67663260  2(2).3(2).5.7.83.647
141.     63022806 2.3(3).7.11.23.659;        64710954  2.3(3).7.11.79.197
142.     63813036 2(2).3.7.17.44687;         64888404  2(2).3.7.41.83.227
143.     64623720 2(3).3.5.7.107.719;        69745560  2(3).3.5.17.179.191
144.     64771938 2.3(2).7.11.17.2749;       77788062  2.3(2). 11.31.299
145.     65156700 2(2).3.5(2).7.19.23.71;    78612900 2(2).3.5(2).31.79.107
146.    *66595130 2.5.7.31.30689;            74824390 2.5.31.59.4091
147.     69405490 2.5.7.11.23.3919;          93164750 2.5(3).7.139.383
148.     69662970-- 2.3(3).5.13.89.223;      72585990 2.3(3).5.41.79.83
149.     70370412 2(2).3.7.17.49279;         71555988 2(2).3.7.41.79.263
150.     71151210 2.3(4).5.13.29.233;        73910070 2.3(4).5.13.7019
151.    *71241830 2.5.11.19.89.383;          78057370 2.5.17.359.1279
152.     71620500 2(2).3.5(3).7.19.359;      73531500- 2(2).3.5(3).7.47.149
153.     72508842 2.3(2).7.17.33851;         73731798 2.3(2).7.53.61.181
154.     72696690 2.3(4).5.11.41.199;        76084110 2.3(4).5.29.41.79
155.     73284900 2(2).3.5(2).13.19.23.43;   80468700 2(2).3.5(2).13.47.439
156.     75139680 2(5).3.5.7.11.19.107;      89089440 2(5).3.5.11.47.359
157.     75729654 2.3(4).7.11.13.467;        79002378 2.3(4).7.13.23.233
158.     76487964 2(2).3.7.17.29.1847;       83179236 2(2).3.7.131.7559
159.    *78447010 2.5.17.19.149.163;         80960990 2.5.11.491.1499
160.     79509870 2.3(3).5.11.19.1409;       91043730 2.3(3).5.449.751
161.     81467820 2(2).3(2).5.7.19.41.83;    87876180 2(2).3(2).5.7.97.719
162.     83093388 2(2).3.7.23.41.1049;       86250612 2(2).3.7.83.89.139
163.     83846532 2(2).3.7.11.103.881;       92271228 2(2).3.7.701.1567
164.     83923320 2(3).3.5.13.23.2339;       85904520 2(3).3.5.1"3.53.1039
165.     84650130-- 2.3(3).5.19.29.569;      87717870 2.3(3).5.19.17099
166.     85305948 2(2).3.7.13.191.409;       91026852 2(2).3.7.59.18367
167.     86075730 2.3(3).5.13.137.179;       89195310 2.3(3).5.19.17387
168.     86490978 2.3.7(2).37.7951;          94814622 2.3(2).7.283.2659
169.     87467160 2(3).3.5.11.23.43.67;      98659176 2(3).3.7.11.197.271
170.    *87998470 2.5.7.29.67.647;           102358010 2.5.47.89.2447
171.     88555698 2.3(2).7.11.181.353;       96996942 2.3(2).7.251.3067
172.     89406702 2.3(2).7.11.251.257;       97839378 2.3(2).7(3).13.23.53
173.     90062700 2(2).3.5(2).7.13.3299;     102129300 2(2).3(2).5(2).7.13.29.43
174.     90716850 2.3(2).5(2).7.31.929;      94985550 2.3(2).5(2).11.31.619;
175.     91250124 2(2).3.7.29.47.797;        92609076 2(2).3.7.37.83.359
176.     91885920 2(5).3.5.7.23.29.41;       99714720 2(5).3.5.7.59.503
177.     94283700 2(2).3.5(2).7.17.19.139;   115380300 2(2).3.5(2).7(2).47.167
178.     94327860 2(2).3.5.11.131.1091;      113239500 2(2).3.5(3).11.6863
179.     95719554 2.3(2).7.17.44687;         97332606 2.3(2).7.41.83.227
180.     95725980 2(2).3(2).5.7.17.41.109;   103858020 2(2).3(2).5.7.139.593
181.    *95791430 2.5.7.17.101.797;          115187002 2.7.17.113.4283
182.     96502140 2(2).3(2).5.7.19.29.139;   105097860 2(2).3(2).5.7.239.349
183.     97292058 2.3.43.439.859;            102503142 2.3(2).7.43.18919
184.     97735050 2.3(2).5(2).7.19.23.71;    117919350 2.3(2).5(2).31.79.107
185.     98324226 2.3(3).7.11.13.17.107;     121145598 2.3(3).7.53.6047
410                                         R.M. NAJAR


Hagis posed five questions of which two bear comment in terms of the UAP’s found.
       Question 3. Is every odd pair of unitary amicable numbers simultaneously amicable?
Only two pairs listed here, numbers 70 and 95, are odd and both are amicable. The evidence
suggests that the answer is "Yes."
       Question 4. If rn 2aM and n 2bN, where MN is odd, is it always the case that a b?
The condition holds for all pairs listed here. Again, the evidence, meager as it is, suggests "Yes."
3.     NEW UNITARY SOCIABLE SETS.
       Flammenkamp [2] discovered eleven new sets of sociable numbers. Eight sets have four
 members; two, eight; and one, nine. We may use

                                     23/(23) 210.3.5.7.41/* (210.3.5.7.41)                     (3.1)

on Flammenkamp’s fifth set to produce a new four element set of unitary sociable numbers.

         58682   84023   96160    2(10).3.5.7.11.19.41.1722307
2.       82978   97587   55840    2(10).3.5.7.17.41.71.343891;
3.       95405   61761   43360    2(10).3.5.7.31.41.13567133;
4.       73443   99131   49440    2(10).3.5.7.41.47.8371211.

The remaining sociable sets in [2] and those listed by Cohen 1] are not amenable to this type of
conversion since a necessary condition of relative primeness fails.

ACKNOWLEDGEMENT. The author wishes to note the assistance of a colleague who prefers to
remain unnamed.

                                      REFERENCES

1. COHEN, H. On Amicable and Sociable Numbers, Mtth. Comp. 2_.4 (1970), 423-429.
2. FLAMMENKAMP, A. New Sociable Numbers, Math. Comp. 56 (1991), 871-873.
3. GARCIA, M. New Unitary Amicable Couples, J. Recreat. Math. 17 (1)(1984-85), 32-35.
4. HAGIS, JR., P. Unitary Amicable Numbers, Math. Comp. 25 (1971), 915-918.
5. MCCLUNG, O. W. Generators of Unitary Amicable Numbers, Fibonaci Quart.
   23 (1985), 158-165.
6. TE RIELE, H.J.J. Computation of all the amicable pairs below      1010, Math Comp. 4..Q7
    (1986), 361-368; $9-$40.
7. WALL, C.R. Topics Related to the Sum of Unitary Divisors of an Integer,
    Dissertation, U. of Tenn. 1970.
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Amicable numbers from 1 to 100000000

  • 1. Internat. J. Math. & Math. Sci. 405 VOL. 18 NO. 2 (1995) 405-410 THE UNITARY AMICABLE PAIRS TO I(P RUDOLPH M. NAJAR Department of Mathematics California State University, Fresno Fresno, CA 93740-0108 (Received January 13, 1993 and in revised form March 19, 1994) ABSTRACT: We present an exhaustive list of the 185 unitary amicable pairs whose smaller number is less than 108 and a new unitary sociable set of four numbers. KEY WORDS AND PHRASES. Unitary amicable pairs, unitary sociable sets. 1991 AMS SUBJECT CLASSIFICATION CODE. 11A25 INTRODUCTION. A unitary amicable pair (UAP) is a pair of integers m, n such that 6*(m) m + n t*(n) (1.1) where t* is the sum of unitary divisors function. In 1971, Hagis [4] published a table of UAP’s, including the results of an exhaustive computer search for all pairs with smaller number less than 106. There were thirty-two UAP’s in the table, none of which were simultaneously ordinary amicable pairs; i.e., which were not square-free. The definitions of unitary amicable pairs and ordinary amicable pairs overlap on square-free pairs. Hagis did not list Wall’s dissertation [7] which included several hundred UAP’s. Since Hagis, several writers (see, for example [3] and [5]) have added to the known UAP’s. UNITARY AMICABLE PAIRS. The present search for UAP’s was conducted on a NeXT station using Mathematica.. Let s*(n) t*(n) n. (2.1) The program searched for numbers k such that s*(s*(k)) k. (2.2) As part of a verification of the program, it initially picked out fixed points of the first ten iterates of s*, thus finding the first four unitary perfect numbers. The search agreed with Hagis’s in finding the nineteen UAP’s less than 106 and the additional four, pairs number 20, 24, 25, and 111 of this list, less than 108 that Hagis listed. The table follows.
  • 2. 406 R.M. NAJAR Square free UAP’s are designated by an asterisk. The square-free UAP’s agree with the ordinary AP’s found in te Riele [6]. Since Wall’s listing [7] was not in numerical order, this list was not compared against his. Total running time is estimated to have exceeded I(X) hours. TABLE OF UNITARY AMICABLE PAIRS TO l08 114 2.3.19; 126 2.3(2).7 2 1140 2(2).3.5.19; 1260 2(2).3(2).5.7 3 18018 2.3(2).7.11.13; 22302 2.3(3).7.59 4 32130-- 2.3(3).5.7.17; 40446 2.3(3).7.107 5 44772 2(2).3.7.13.41; 49308 2(2).3.7.587 6 56430 2.3(3).5.11.19; 64530 2.3(3).5.239 7 67158 2.3(2).7.13.41; 73962 2.3(2).7.587 8 *142310 2.5.7.19.107; 168730 2.5.47.359 9. 180180 2(2).3(2).5.7.11.13; 223020 2(2).3(3).5.7.59 10. 197340 2(2).3.5.11.13.23; 286500 2(2).3.5(3).191 11. 241110 2.3(3).5.19.47; 242730 2.3(3).5.29.31 12. 296010 2.3(2).5.11.13.23; 429750 2.3(2).5(3).191 13. 308220 2(2).3.5.11.467; 365700 2(2).3.5(2).23.53 14. 462330 2.3(2).5.11.467; 548550 2.3(2).5(2).23.53 15. 591030 2.3(3).5.11.199; 618570 2.3(3).5.29.79 16. 669900 2(2).3.5(2).7.11.29; 827700 2(2).3.5(2).31.89 17. 671580 2(2).3(2).5.7.13.41; 739620 2(2).3(2).5.7.587 18. 785148 2(2).3.7.13.719; 827652 2(2).3.7.59.167 19. 815100 2(2).3.5(2).11.13.19; 932100 2(2).3.5(2).13.239 20. 1004850 2.3(2).5(2).7.11.29; 1241550 2.3(2).5(2).31.89 21. *1077890 2.5.11.41.239; 1099390 2.5.17.29.223 22. 1080150 2.3.5(2).19.379; 1291050 2.3(2).5(2).19.151 23. * 1156870 2.5.11.13.809; 1292570 2.5.19.6803 24. 1177722 2.3(2).7.13.719; 1241478 2.3(2).7.59.167 25. 1222650 2.3(2).5(2).11.13.19; 1398150 2.3(2).5(2).13.239 26. 1281540 2(2).3.5.13.31.53; 1621500 2(2).3.5(3).23.47 27. 1475810 2.5.7.29.727; 1669150 2.5(2).7.19.251 28. * 1511930 2.5.7.21599; 1598470 2.5.19.47.179 29. 1571388 2(2).3.7.13.1439; 1654212 2(2).3.7.47.419 30. 1610700 2(2).3.5(2).7.13.59; 1883700 2(2).3(2).5(2).7.13.23 31. *1669910 2.5.11.17.19.47; 2062570 2.5.239.863 32. 1707720 2(3).3.5.7.19.107; 2024760 2(3).3.5.47.359 33. 1908420 2(2).3.5.17.1871; 2135100 2(2).3.5(2).11.647 34. 1922310 2.3(2).5.13.31.53; 2432250 2.3(2).5(3).23.47 35. 1997520 2(4).3.5.7.29.41; 2115120 2(4).3.5.7.1259 36. *2236570 2.5.7.89.359; 2429030 2.5.23.59.179 37. 2357082 2.3(2).7.13.1439; 2481318 2.3(2).7.47.419 38. *2728726 2.7.11.13.29.47; 3077354 2.7.19.23.503 39. 2862630- 2.3(3).5.17.1871; 3202650 2.3(2).5(2).11.647 40. 3406116 2(2).3.7.23.41.43; 3690204 2(2).3.7.197.223 41. 3482700 2(2).3.5(2).13.19.47; 3506100 2(2).3.5(2).13.29.31 42. 3951990 2.3(4).5.7.17.41; 49748:8 2.3(4).7.41.107
  • 3. UNITARY AMICABLE PAIRS 407 43. 4198236 2(2).3.7.23.41.53; 4510884 2(2).3.7.83.647 44. "4246130 2.5.7.60659; 4488910 2.5.23.29.673 45. 4439890 2.5.7(2).13.17.41; 5085710 2.5.7(2).97.107 46. *4532710 2.5.7.13.17.293; 6135962 2.7.71.6173 47. 4918550 2.5(2).7.13.23.47; 5145322 2.7.13.17.1663 48. 5073570 2.3(3).5.19.23.43; 5570910 2.3(3).5.47.43 49. 5109174 2.3(2).7.23.41.43; 5535306 2.3(2).7.197.223 50. *5123090 2.5.7.163.449; 5504110- 2.5.19.59.491 51. 5191290 2.3(4).5.13.17.29; 5967270 2.3(4).5.53.139 52. 5224050 2.3(2).5(2).13.19.47; 5259150 2.3(2).5(2).13.29.31 53. 5341620 2(2).3.5.127.701; 5441100 2(2).3.5(2).7.2591 54. *5385310- 2.5.7.107.719; 5812130 2.5.17.179.191 55. 5431188 2(2).3.7.19.41.83; 5858412 2(2).3.7.97.719 56. 6297354 2.3(2).7.23.41.53; 6766326 2.3(2).7.83.647 57. 6381732 2(2).3.7.17.41.109; 6923868 2(2).3.7.139.593 58. 6433476 2(2).3.7.19.29.139; 7006524 2(2).3.7.239.349 59. 6940890 2.3(4).5.11.19.41; 7937190 2.3(4).5.41.239 60. *6993610 2.5.13.23.2339; 7158710-- 2.5.13.53.1039 61. 7051590 2.3(3).5.7(2).13.41; 7766010 2.3(3).5.7(2).587 62. *7288930 2.5.11.23.43.67; 8221598 2.7.11.197.271 63. 7929012 2(2).3.7.13.53.137; 8763468 2(2).3.7.104327 64. 8012430 2.3(2).5.127.701; 8161650 2.3(2).5(2).7.2591 65. 8095620 2(2).3.5.13.97.107; 9685500 2(2).3.5(3).11.587 66. 8146782 2.3(2).7.19.41.83; 8787618 2.3(2).7.97.719 67. 8194230 2.3(3).5.11.31.89; 9224010 2.3(3).5.127.269 68. 8235810 2.3(3).5.11.47.59; 9182430 2.3(3).5.71.479 69. 8537100 2(2).3.5(2).11.13.199; 8934900 2(2).3.5(2). 13.29.79 70. *8619765 3.5.7.11.17.439; 9627915 3.5.11.23.43.59 71. *8754130 2.5.7.11.11369; 10893230 2.5.757.1439 72. *8826070 2.5.11.19.41.103; 10043690 2.5.31.179.181 73. 9057300 2(2).3.5(2).7.19.227; 9912300- 2(2).3.5(2).19.37.47 74. *9478910 2.5.7.19.7127; 11049730 2.5.71.79.197 75. 9572598 2.3(2).7.17.41.109; 10385802 2.3(2).7.139.593 76. 9650214 2.3(2).7.19.29.139; 10509786 2.3(2).7.239.349 77. 9680310 2.3(4).5.17.19.37; 10511370 2.3(4).5.19.683 78. 9701076 2(2).3.7.11.10499; 10458924 2(2).3.7.89.1399 79.* 10254970 2.5.11.53.1759; 10273670 2.5.11.59.1583 80. 11777220 2(2).3(2).5.7.13.719; 12414780 2(2).3(2).5.7.59.167 81. 11893518 2.3(2).7.13.53.137; 13145202 2.3(2).7.104327 82. 12143430 2.3(2).5.13.97.107; 14528250 2.3(2).5(3).11.587 83. 12805650 2.3(2).5(2).11.13.199; 13402350 2.3(2).5(2).13.29.79 84. 12934680 2(3).3.5.11.41.239; 13192680 2(3).3.5.17.29.223 85. 13321490 2.5.7.13.14639; 16192750 2.5(3).7.19.487 86. 13585950 2.3(2).5(2).7.19.227; 14868450 2.3(2).5(2). 19.37.47 87. 13882440 2(3).3.5.11.13.809; 15510840 2(3).3.5.19.6803 88. 14257020 2(2).3.5.127.1871; 14496900 2(2).3.5(2).11.23.191 89. *14426230 2.5.7.13.83.191; 18087818 2.7.31.71.587 90. 14551614 2.3(2).7.11.10499; 15688386 2.3(2).7.89.1399
  • 4. 408 R.M. NAJAR 91 14634270 2.3(4).5.7.29.89; 17247330 2.3(4).5.107.199 92. 16045722 2.3(3).7.11.17.227; 17048934 2.3(3).7.23.37.53 93. 16326090 2.3(3).5.11.23.239; 18510390 2.3(3).5.179.383 94. *17041010 2.5.7.31.7853; 19150222 2.7.13.43.2447 95. * 17257695 3.5.7.13.47.269; 17578785 3.5.7.23.29.251 96. 17278548 2(2).3.7.29.41.173; 17799852 2(2).3.7.29.7307 97. 17468730 2.3(3).5.23.29.97; 18093510 2.3(3).5.19.3527 98. 17709720 2(3).3.5.7.29.727; 20029800 2(3).3.5(2).7.19.251 99. 18143160 2(3).3.5.7.21599; 19181640 2(3).3.5.19.47.179 100. 20038920 2(3).3.5.11.17.19.47; 24750840 2(3).3.5.239.863 101. 21385530 2.3(2).5.127.1871; 21745350 2.3(2).5(2).11.23.191 102. *21448630 2.5.7.131.2339; 23030090 2.5.19.53.2287 103. 21705684 2(2).3.7.11.13(2).139; 23990316 2(2).3.7.285599 104. 23570820 2(2).3(2).5.7.13.1439; 24813180 2(2).3(2).5.7.47.419 105. 24542700 2(2).3.5(2).7.13.29.31; 31367700 2(2).3(2).5(2).7.13.383 106. 25425876 2(2).3.7.19.89.179; 26414124 2(2).3.11.17.79.149 107. 25917822 2.3(2).7.29.41.173; 26699778 2.3(2).7.29.7307 108. 26355084 2(2).3.7.29.31.349; 27404916 2(2).3.7(2).11.19.223 109. 26791830 2.3(3).5.13.17.449; 30361770 2.3(3).5.139.809 110. 26838840 2(3).3.5.7.89.359; 29148360- 2(3).3.5.23.59.179 111. 27287260 2(2).5.7.11.13.29.47; 30773540 2(2).5.7.19.23.503 112. 29408130 2.3(3).5.17.43.149; 30467070 2.3(3).5.19.5939 113. 29656530 2.3(4).5.19.41.47; 29855790 2.3(4).5.29.31.41 114. *30724694 2.7.11.13.103.149; 32174506 2.7.13.17.10399 115. 31035550 2.5(2).7.13.19.359; 31863650 2.5(2).7.13.47.149 116. 32558526 2.3(2).7.11.13(2).139; 35985474 2.3(2).7.285599 117. 32744712 2(3).3.7.11.13.29.47; 36928248 2(3).3.7.19.23.503 118. *34256222 2.7.11.13.71.241; 35997346 2.7.11.23.10163 119. *35361326 2.7.11.13.17.1039; 40117714 2.7.13.53.4159 120. *37784810 2.5.7.539783; 39944086 2.7.13.41.53.101 121. 38138310 2.3(3).5.7.17.1187; 48081978 2.3(3).7.131.971 122. 38138814 2.3(2).7.19.89.179; 39621186 2.3(2).11.17.79.149 123. 39532626 2.3(2).7.29.31.349; 41107374 2.3(2).7(2).11.19.223 124. 40880532 2(2).3.7.11.151.293; 44920428 2(2).3.7.607.881 125. 42740880 2(4).3.5.7.13.19.103; 52306800 2(4).3.5(2).7.13.479 126. 43181292 2(2).3.7.11.17.2749; 51858708 2(2).3.11.131.2999 127. 48339228 2(2).3.7.17.33851; 49154532 2(2).3.7.53.61.181 128. 49117590 2.3(5).5.17.29.41; 50492970 2.3(5).5.11.1889 129. 50953560 2(3).3.5.7.60659; 53866920 2(3).3.5.23.29.673 130. 51091740- 2(2).3(2).5.7.23.41.43; 55353060 2(2).3(2).5.7.197.223 131. 53278680 2(3).3.5.7(2).13.17.41; 61028520 2(3).3.5.7(2).97.107 132. 54392520- 2(3).3.5.7.13.17.293; 73631544 2(3).3.7.71.6173 133. 58062480 2(4).3.5.7.17.19.107; 68841840- 2(4).3.5.17.47.359 134. 59022600 2(3).3.5(2).7.13.23.47; 61743864 2(3).3.7.13.17.1663 135. 59037132 2(2).3.7.11.181.353; 64664628 2(2).3.7.251.3067 136. 59604468 2(2).3.7.11.251.257; 65226252 2(2).3.7(3).13.23.53 137. 60477900 2(2).3.5(2).7.31.929; 63323700 2(2).3.5(2).11.31.619 138. 61320798 2.3(2).7.11.151.293; 67380642 2.3(2).7.607.881
  • 5. UNITARY AMICABLE PAIRS 409 139. 61477080 2(3).3.5.7.163.449; 66049320 2(3).3.5.19.59.491 140. 62973540 2(2).3(2).5.7.23.41.53; 67663260 2(2).3(2).5.7.83.647 141. 63022806 2.3(3).7.11.23.659; 64710954 2.3(3).7.11.79.197 142. 63813036 2(2).3.7.17.44687; 64888404 2(2).3.7.41.83.227 143. 64623720 2(3).3.5.7.107.719; 69745560 2(3).3.5.17.179.191 144. 64771938 2.3(2).7.11.17.2749; 77788062 2.3(2). 11.31.299 145. 65156700 2(2).3.5(2).7.19.23.71; 78612900 2(2).3.5(2).31.79.107 146. *66595130 2.5.7.31.30689; 74824390 2.5.31.59.4091 147. 69405490 2.5.7.11.23.3919; 93164750 2.5(3).7.139.383 148. 69662970-- 2.3(3).5.13.89.223; 72585990 2.3(3).5.41.79.83 149. 70370412 2(2).3.7.17.49279; 71555988 2(2).3.7.41.79.263 150. 71151210 2.3(4).5.13.29.233; 73910070 2.3(4).5.13.7019 151. *71241830 2.5.11.19.89.383; 78057370 2.5.17.359.1279 152. 71620500 2(2).3.5(3).7.19.359; 73531500- 2(2).3.5(3).7.47.149 153. 72508842 2.3(2).7.17.33851; 73731798 2.3(2).7.53.61.181 154. 72696690 2.3(4).5.11.41.199; 76084110 2.3(4).5.29.41.79 155. 73284900 2(2).3.5(2).13.19.23.43; 80468700 2(2).3.5(2).13.47.439 156. 75139680 2(5).3.5.7.11.19.107; 89089440 2(5).3.5.11.47.359 157. 75729654 2.3(4).7.11.13.467; 79002378 2.3(4).7.13.23.233 158. 76487964 2(2).3.7.17.29.1847; 83179236 2(2).3.7.131.7559 159. *78447010 2.5.17.19.149.163; 80960990 2.5.11.491.1499 160. 79509870 2.3(3).5.11.19.1409; 91043730 2.3(3).5.449.751 161. 81467820 2(2).3(2).5.7.19.41.83; 87876180 2(2).3(2).5.7.97.719 162. 83093388 2(2).3.7.23.41.1049; 86250612 2(2).3.7.83.89.139 163. 83846532 2(2).3.7.11.103.881; 92271228 2(2).3.7.701.1567 164. 83923320 2(3).3.5.13.23.2339; 85904520 2(3).3.5.1"3.53.1039 165. 84650130-- 2.3(3).5.19.29.569; 87717870 2.3(3).5.19.17099 166. 85305948 2(2).3.7.13.191.409; 91026852 2(2).3.7.59.18367 167. 86075730 2.3(3).5.13.137.179; 89195310 2.3(3).5.19.17387 168. 86490978 2.3.7(2).37.7951; 94814622 2.3(2).7.283.2659 169. 87467160 2(3).3.5.11.23.43.67; 98659176 2(3).3.7.11.197.271 170. *87998470 2.5.7.29.67.647; 102358010 2.5.47.89.2447 171. 88555698 2.3(2).7.11.181.353; 96996942 2.3(2).7.251.3067 172. 89406702 2.3(2).7.11.251.257; 97839378 2.3(2).7(3).13.23.53 173. 90062700 2(2).3.5(2).7.13.3299; 102129300 2(2).3(2).5(2).7.13.29.43 174. 90716850 2.3(2).5(2).7.31.929; 94985550 2.3(2).5(2).11.31.619; 175. 91250124 2(2).3.7.29.47.797; 92609076 2(2).3.7.37.83.359 176. 91885920 2(5).3.5.7.23.29.41; 99714720 2(5).3.5.7.59.503 177. 94283700 2(2).3.5(2).7.17.19.139; 115380300 2(2).3.5(2).7(2).47.167 178. 94327860 2(2).3.5.11.131.1091; 113239500 2(2).3.5(3).11.6863 179. 95719554 2.3(2).7.17.44687; 97332606 2.3(2).7.41.83.227 180. 95725980 2(2).3(2).5.7.17.41.109; 103858020 2(2).3(2).5.7.139.593 181. *95791430 2.5.7.17.101.797; 115187002 2.7.17.113.4283 182. 96502140 2(2).3(2).5.7.19.29.139; 105097860 2(2).3(2).5.7.239.349 183. 97292058 2.3.43.439.859; 102503142 2.3(2).7.43.18919 184. 97735050 2.3(2).5(2).7.19.23.71; 117919350 2.3(2).5(2).31.79.107 185. 98324226 2.3(3).7.11.13.17.107; 121145598 2.3(3).7.53.6047
  • 6. 410 R.M. NAJAR Hagis posed five questions of which two bear comment in terms of the UAP’s found. Question 3. Is every odd pair of unitary amicable numbers simultaneously amicable? Only two pairs listed here, numbers 70 and 95, are odd and both are amicable. The evidence suggests that the answer is "Yes." Question 4. If rn 2aM and n 2bN, where MN is odd, is it always the case that a b? The condition holds for all pairs listed here. Again, the evidence, meager as it is, suggests "Yes." 3. NEW UNITARY SOCIABLE SETS. Flammenkamp [2] discovered eleven new sets of sociable numbers. Eight sets have four members; two, eight; and one, nine. We may use 23/(23) 210.3.5.7.41/* (210.3.5.7.41) (3.1) on Flammenkamp’s fifth set to produce a new four element set of unitary sociable numbers. 58682 84023 96160 2(10).3.5.7.11.19.41.1722307 2. 82978 97587 55840 2(10).3.5.7.17.41.71.343891; 3. 95405 61761 43360 2(10).3.5.7.31.41.13567133; 4. 73443 99131 49440 2(10).3.5.7.41.47.8371211. The remaining sociable sets in [2] and those listed by Cohen 1] are not amenable to this type of conversion since a necessary condition of relative primeness fails. ACKNOWLEDGEMENT. The author wishes to note the assistance of a colleague who prefers to remain unnamed. REFERENCES 1. COHEN, H. On Amicable and Sociable Numbers, Mtth. Comp. 2_.4 (1970), 423-429. 2. FLAMMENKAMP, A. New Sociable Numbers, Math. Comp. 56 (1991), 871-873. 3. GARCIA, M. New Unitary Amicable Couples, J. Recreat. Math. 17 (1)(1984-85), 32-35. 4. HAGIS, JR., P. Unitary Amicable Numbers, Math. Comp. 25 (1971), 915-918. 5. MCCLUNG, O. W. Generators of Unitary Amicable Numbers, Fibonaci Quart. 23 (1985), 158-165. 6. TE RIELE, H.J.J. Computation of all the amicable pairs below 1010, Math Comp. 4..Q7 (1986), 361-368; $9-$40. 7. WALL, C.R. Topics Related to the Sum of Unitary Divisors of an Integer, Dissertation, U. of Tenn. 1970.
  • 7. Mathematical Problems in Engineering Special Issue on Time-Dependent Billiards Call for Papers This subject has been extensively studied in the past years Guest Editors for one-, two-, and three-dimensional space. Additionally, Edson Denis Leonel, Department of Statistics, Applied such dynamical systems can exhibit a very important and still Mathematics and Computing, Institute of Geosciences and unexplained phenomenon, called as the Fermi acceleration Exact Sciences, State University of São Paulo at Rio Claro, phenomenon. Basically, the phenomenon of Fermi accelera- Avenida 24A, 1515 Bela Vista, 13506-700 Rio Claro, SP, tion (FA) is a process in which a classical particle can acquire Brazil; edleonel@rc.unesp.br unbounded energy from collisions with a heavy moving wall. This phenomenon was originally proposed by Enrico Fermi Alexander Loskutov, Physics Faculty, Moscow State in 1949 as a possible explanation of the origin of the large University, Vorob’evy Gory, Moscow 119992, Russia; energies of the cosmic particles. His original model was loskutov@chaos.phys.msu.ru then modified and considered under different approaches and using many versions. Moreover, applications of FA have been of a large broad interest in many different fields of science including plasma physics, astrophysics, atomic physics, optics, and time-dependent billiard problems and they are useful for controlling chaos in Engineering and dynamical systems exhibiting chaos (both conservative and dissipative chaos). We intend to publish in this special issue papers reporting research on time-dependent billiards. The topic includes both conservative and dissipative dynamics. Papers dis- cussing dynamical properties, statistical and mathematical results, stability investigation of the phase space structure, the phenomenon of Fermi acceleration, conditions for having suppression of Fermi acceleration, and computational and numerical methods for exploring these structures and applications are welcome. To be acceptable for publication in the special issue of Mathematical Problems in Engineering, papers must make significant, original, and correct contributions to one or more of the topics above mentioned. Mathematical papers regarding the topics above are also welcome. Authors should follow the Mathematical Problems in Engineering manuscript format described at http://www .hindawi.com/journals/mpe/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http:// mts.hindawi.com/ according to the following timetable: Manuscript Due March 1, 2009 First Round of Reviews June 1, 2009 Publication Date September 1, 2009 Hindawi Publishing Corporation http://www.hindawi.com