A307320 - cp's OEIS frontend

A307320 a(n) is the base-2 logarithm of the denominator of sigma_{-1}(P(n)), where P(n) = 2^(n-1)*M(n), where M(n) = 2^n - 1 is the n-th Mersenne number.

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	2
7	0
8	3
9	4
10	0
11	6
12	6
13	0
14	2
15	3
16	10
17	0
18	8
19	0
20	9
21	12
22	13
23	17
24	16
25	17
26	8
27	21
28	13
29	22
30	14
31	0
32	25
33	22
34	12
35	18
36	22
37	30
38	14
39	17
40	27
41	36
42	29
43	32
44	32
45	25
46	36
47	40
48	37
49	40
50	34
51	18
52	30
53	47
54	44
55	40
56	39
57	29
58	46
59	53
60	40
61	0
62	26
63	51
64	55
65	41
66	50
67	62
68	42
69	57
70	44
71	61

[0, 0, 0, 0, 0, 2, 0, 3, 4, 0, 6, 6, 0, 2, 3, 10, 0, 8, 0, 9, 12, 13, 17, 16, 17, 8, 21, 13, 22, 14, 0, 25, 22, 12, 18, 22, 30, 14, 17, 27, 36, 29, 32, 32, 25, 36, 40, 37, 40, 34, 18, 30, 47, 44, 40, 39, 29, 46, 53, 40, 0, 26, 51, 55, 41, 50, 62, 42, 57, 44, 61]

cp's OEIS Frontend

A307320 a(n) is the base-2 logarithm of the denominator of sigma_{-1}(P(n)), where P(n) = 2^(n-1)*M(n), where M(n) = 2^n - 1 is the n-th Mersenne number.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	2
7	0
8	3
9	4
10	0
11	6
12	6
13	0
14	2
15	3
16	10
17	0
18	8
19	0
20	9
21	12
22	13
23	17
24	16
25	17
26	8
27	21
28	13
29	22
30	14
31	0
32	25
33	22
34	12
35	18
36	22
37	30
38	14
39	17
40	27
41	36
42	29
43	32
44	32
45	25
46	36
47	40
48	37
49	40
50	34
51	18
52	30
53	47
54	44
55	40
56	39
57	29
58	46
59	53
60	40
61	0
62	26
63	51
64	55
65	41
66	50
67	62
68	42
69	57
70	44
71	61

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	2
7	0
8	3
9	4
10	0
11	6
12	6
13	0
14	2
15	3
16	10
17	0
18	8
19	0
20	9
21	12
22	13
23	17
24	16
25	17
26	8
27	21
28	13
29	22
30	14
31	0
32	25
33	22
34	12
35	18
36	22
37	30
38	14
39	17
40	27
41	36
42	29
43	32
44	32
45	25
46	36
47	40
48	37
49	40
50	34
51	18
52	30
53	47
54	44
55	40
56	39
57	29
58	46
59	53
60	40
61	0
62	26
63	51
64	55
65	41
66	50
67	62
68	42
69	57
70	44
71	61

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	2
7	0
8	3
9	4
10	0
11	6
12	6
13	0
14	2
15	3
16	10
17	0
18	8
19	0
20	9
21	12
22	13
23	17
24	16
25	17
26	8
27	21
28	13
29	22
30	14
31	0
32	25
33	22
34	12
35	18
36	22
37	30
38	14
39	17
40	27
41	36
42	29
43	32
44	32
45	25
46	36
47	40
48	37
49	40
50	34
51	18
52	30
53	47
54	44
55	40
56	39
57	29
58	46
59	53
60	40
61	0
62	26
63	51
64	55
65	41
66	50
67	62
68	42
69	57
70	44
71	61