A298908 - cp's OEIS frontend

A298908 Smallest composite k such that (n^k - 1)/(n - 1) == 1 (mod k) for n > 1.

n	a(n)
2	341
3	91
4	4
5	15
6	6
7	25
8	4
9	9
10	10
11	33
12	4
13	65
14	14
15	15
16	4
17	9
18	6
19	49
20	4
21	21
22	22
23	69
24	4
25	25
26	9
27	9
28	4
29	15
30	6
31	49
32	4
33	33
34	34
35	9
36	4
37	133
38	38
39	15
40	4
41	21
42	6
43	25
44	4
45	9
46	46
47	65
48	4
49	25
50	10
51	39
52	4
53	9
54	6
55	35
56	4
57	25
58	58
59	15
60	4
61	91
62	9
63	9
64	4
65	15
66	6
67	49
68	4
69	15
70	10
71	9
72	4
73	65
74	15
75	15
76	4
77	21
78	6
79	49
80	4
81	9

[341, 91, 4, 15, 6, 25, 4, 9, 10, 33, 4, 65, 14, 15, 4, 9, 6, 49, 4, 21, 22, 69, 4, 25, 9, 9, 4, 15, 6, 49, 4, 33, 34, 9, 4, 133, 38, 15, 4, 21, 6, 25, 4, 9, 46, 65, 4, 25, 10, 39, 4, 9, 6, 35, 4, 25, 58, 15, 4, 91, 9, 9, 4, 15, 6, 49, 4, 15, 10, 9, 4, 65, 15, 15, 4, 21, 6, 49, 4, 9]

cp's OEIS Frontend

A298908 Smallest composite k such that (n^k - 1)/(n - 1) == 1 (mod k) for n > 1.

Table of values

List of values

n	a(n)
2	341
3	91
4	4
5	15
6	6
7	25
8	4
9	9
10	10
11	33
12	4
13	65
14	14
15	15
16	4
17	9
18	6
19	49
20	4
21	21
22	22
23	69
24	4
25	25
26	9
27	9
28	4
29	15
30	6
31	49
32	4
33	33
34	34
35	9
36	4
37	133
38	38
39	15
40	4
41	21
42	6
43	25
44	4
45	9
46	46
47	65
48	4
49	25
50	10
51	39
52	4
53	9
54	6
55	35
56	4
57	25
58	58
59	15
60	4
61	91
62	9
63	9
64	4
65	15
66	6
67	49
68	4
69	15
70	10
71	9
72	4
73	65
74	15
75	15
76	4
77	21
78	6
79	49
80	4
81	9

n	a(n)
2	341
3	91
4	4
5	15
6	6
7	25
8	4
9	9
10	10
11	33
12	4
13	65
14	14
15	15
16	4
17	9
18	6
19	49
20	4
21	21
22	22
23	69
24	4
25	25
26	9
27	9
28	4
29	15
30	6
31	49
32	4
33	33
34	34
35	9
36	4
37	133
38	38
39	15
40	4
41	21
42	6
43	25
44	4
45	9
46	46
47	65
48	4
49	25
50	10
51	39
52	4
53	9
54	6
55	35
56	4
57	25
58	58
59	15
60	4
61	91
62	9
63	9
64	4
65	15
66	6
67	49
68	4
69	15
70	10
71	9
72	4
73	65
74	15
75	15
76	4
77	21
78	6
79	49
80	4
81	9

n	a(n)
2	341
3	91
4	4
5	15
6	6
7	25
8	4
9	9
10	10
11	33
12	4
13	65
14	14
15	15
16	4
17	9
18	6
19	49
20	4
21	21
22	22
23	69
24	4
25	25
26	9
27	9
28	4
29	15
30	6
31	49
32	4
33	33
34	34
35	9
36	4
37	133
38	38
39	15
40	4
41	21
42	6
43	25
44	4
45	9
46	46
47	65
48	4
49	25
50	10
51	39
52	4
53	9
54	6
55	35
56	4
57	25
58	58
59	15
60	4
61	91
62	9
63	9
64	4
65	15
66	6
67	49
68	4
69	15
70	10
71	9
72	4
73	65
74	15
75	15
76	4
77	21
78	6
79	49
80	4
81	9