A260757 - cp's OEIS frontend

A260757 Least k > 0 such that M(n)^2 - 2k is prime, where M(n) = 2^n - 1 = A000225(n).

n	a(n)
0	1
1	2
2	1
3	1
4	1
5	4
6	1
7	1
8	7
9	10
10	1
11	10
12	1
13	10
14	5
15	1
16	14
17	24
18	1
19	1
20	13
21	1
22	16
23	3
24	82
25	1
26	19
27	1
28	23
29	94
30	64
31	58
32	7
33	6
34	14
35	3
36	46
37	22
38	5
39	13
40	107
41	69
42	38
43	90
44	59
45	75
46	104
47	25
48	4
49	10
50	14
51	4
52	44
53	10
54	5
55	1
56	77
57	81
58	85
59	94
60	71
61	9
62	14
63	111
64	13
65	27
66	20
67	9
68	37
69	6
70	5
71	4
72	62
73	12
74	38
75	4
76	37

[1, 2, 1, 1, 1, 4, 1, 1, 7, 10, 1, 10, 1, 10, 5, 1, 14, 24, 1, 1, 13, 1, 16, 3, 82, 1, 19, 1, 23, 94, 64, 58, 7, 6, 14, 3, 46, 22, 5, 13, 107, 69, 38, 90, 59, 75, 104, 25, 4, 10, 14, 4, 44, 10, 5, 1, 77, 81, 85, 94, 71, 9, 14, 111, 13, 27, 20, 9, 37, 6, 5, 4, 62, 12, 38, 4, 37]

cp's OEIS Frontend

A260757 Least k > 0 such that M(n)^2 - 2k is prime, where M(n) = 2^n - 1 = A000225(n).

Table of values

List of values

n	a(n)
0	1
1	2
2	1
3	1
4	1
5	4
6	1
7	1
8	7
9	10
10	1
11	10
12	1
13	10
14	5
15	1
16	14
17	24
18	1
19	1
20	13
21	1
22	16
23	3
24	82
25	1
26	19
27	1
28	23
29	94
30	64
31	58
32	7
33	6
34	14
35	3
36	46
37	22
38	5
39	13
40	107
41	69
42	38
43	90
44	59
45	75
46	104
47	25
48	4
49	10
50	14
51	4
52	44
53	10
54	5
55	1
56	77
57	81
58	85
59	94
60	71
61	9
62	14
63	111
64	13
65	27
66	20
67	9
68	37
69	6
70	5
71	4
72	62
73	12
74	38
75	4
76	37

n	a(n)
0	1
1	2
2	1
3	1
4	1
5	4
6	1
7	1
8	7
9	10
10	1
11	10
12	1
13	10
14	5
15	1
16	14
17	24
18	1
19	1
20	13
21	1
22	16
23	3
24	82
25	1
26	19
27	1
28	23
29	94
30	64
31	58
32	7
33	6
34	14
35	3
36	46
37	22
38	5
39	13
40	107
41	69
42	38
43	90
44	59
45	75
46	104
47	25
48	4
49	10
50	14
51	4
52	44
53	10
54	5
55	1
56	77
57	81
58	85
59	94
60	71
61	9
62	14
63	111
64	13
65	27
66	20
67	9
68	37
69	6
70	5
71	4
72	62
73	12
74	38
75	4
76	37

n	a(n)
0	1
1	2
2	1
3	1
4	1
5	4
6	1
7	1
8	7
9	10
10	1
11	10
12	1
13	10
14	5
15	1
16	14
17	24
18	1
19	1
20	13
21	1
22	16
23	3
24	82
25	1
26	19
27	1
28	23
29	94
30	64
31	58
32	7
33	6
34	14
35	3
36	46
37	22
38	5
39	13
40	107
41	69
42	38
43	90
44	59
45	75
46	104
47	25
48	4
49	10
50	14
51	4
52	44
53	10
54	5
55	1
56	77
57	81
58	85
59	94
60	71
61	9
62	14
63	111
64	13
65	27
66	20
67	9
68	37
69	6
70	5
71	4
72	62
73	12
74	38
75	4
76	37