A306270 - cp's OEIS frontend

A306270 Composite numbers k such that b^(k(k-1)) == 1 (mod k^2) for every b coprime to k.

n	a(n)
1	4
2	6
3	12
4	20
5	21
6	28
7	42
8	52
9	60
10	66
11	84
12	105
13	156
14	165
15	186
16	220
17	231
18	273
19	276
20	301
21	364
22	385
23	420
24	465
25	506
26	532
27	561
28	609
29	645
30	651
31	660
32	780
33	804
34	903
35	946
36	1036
37	1045
38	1065
39	1092
40	1105
41	1204
42	1265
43	1281
44	1365
45	1491
46	1540
47	1705
48	1716
49	1729
50	1771
51	1806
52	1860

[4, 6, 12, 20, 21, 28, 42, 52, 60, 66, 84, 105, 156, 165, 186, 220, 231, 273, 276, 301, 364, 385, 420, 465, 506, 532, 561, 609, 645, 651, 660, 780, 804, 903, 946, 1036, 1045, 1065, 1092, 1105, 1204, 1265, 1281, 1365, 1491, 1540, 1705, 1716, 1729, 1771, 1806, 1860]

cp's OEIS Frontend

A306270 Composite numbers k such that b^(k(k-1)) == 1 (mod k^2) for every b coprime to k.

Table of values

List of values