A270600 - cp's OEIS frontend

A270600 a(n) is the smallest k > 1 not already in the sequence such that p = prime(n) is a factor of 2^k-1.

n	a(n)
2	2
3	4
4	3
5	10
6	12
7	8
8	18
9	11
10	28
11	5
12	36
13	20
14	14
15	23
16	52
17	58
18	60
19	66
20	35
21	9
22	39
23	82
24	22
25	48
26	100
27	51
28	106
29	72
30	56
31	7
32	130
33	68
34	138
35	148
36	15
37	104
38	162
39	83
40	172
41	178
42	180
43	95
44	96
45	196
46	99
47	210
48	37
49	226
50	76
51	29

[2, 4, 3, 10, 12, 8, 18, 11, 28, 5, 36, 20, 14, 23, 52, 58, 60, 66, 35, 9, 39, 82, 22, 48, 100, 51, 106, 72, 56, 7, 130, 68, 138, 148, 15, 104, 162, 83, 172, 178, 180, 95, 96, 196, 99, 210, 37, 226, 76, 29]

cp's OEIS Frontend

A270600 a(n) is the smallest k > 1 not already in the sequence such that p = prime(n) is a factor of 2^k-1.

Table of values

List of values

n	a(n)
2	2
3	4
4	3
5	10
6	12
7	8
8	18
9	11
10	28
11	5
12	36
13	20
14	14
15	23
16	52
17	58
18	60
19	66
20	35
21	9
22	39
23	82
24	22
25	48
26	100
27	51
28	106
29	72
30	56
31	7
32	130
33	68
34	138
35	148
36	15
37	104
38	162
39	83
40	172
41	178
42	180
43	95
44	96
45	196
46	99
47	210
48	37
49	226
50	76
51	29

n	a(n)
2	2
3	4
4	3
5	10
6	12
7	8
8	18
9	11
10	28
11	5
12	36
13	20
14	14
15	23
16	52
17	58
18	60
19	66
20	35
21	9
22	39
23	82
24	22
25	48
26	100
27	51
28	106
29	72
30	56
31	7
32	130
33	68
34	138
35	148
36	15
37	104
38	162
39	83
40	172
41	178
42	180
43	95
44	96
45	196
46	99
47	210
48	37
49	226
50	76
51	29

n	a(n)
2	2
3	4
4	3
5	10
6	12
7	8
8	18
9	11
10	28
11	5
12	36
13	20
14	14
15	23
16	52
17	58
18	60
19	66
20	35
21	9
22	39
23	82
24	22
25	48
26	100
27	51
28	106
29	72
30	56
31	7
32	130
33	68
34	138
35	148
36	15
37	104
38	162
39	83
40	172
41	178
42	180
43	95
44	96
45	196
46	99
47	210
48	37
49	226
50	76
51	29