A140769 - cp's OEIS frontend

A140769 Numbers n such that consecutive Mersenne numbers A000225(n-1) = M(n-1) = 2^(n-1) - 1 and A000225(n) = M(n) = 2^n - 1 are both squarefree.

n	a(n)
1	2
2	3
3	4
4	5
5	8
6	9
7	10
8	11
9	14
10	15
11	16
12	17
13	23
14	26
15	27
16	28
17	29
18	32
19	33
20	34
21	35
22	38
23	39
24	44
25	45
26	46
27	47
28	50
29	51
30	52
31	53
32	56
33	57
34	58
35	59
36	62
37	65
38	68
39	69
40	70
41	71
42	74
43	75
44	76
45	77
46	82
47	83
48	86
49	87
50	88
51	89
52	92
53	93
54	94
55	95
56	98
57	99
58	104
59	107
60	112
61	113
62	116
63	117
64	118
65	119
66	122
67	123
68	124

[2, 3, 4, 5, 8, 9, 10, 11, 14, 15, 16, 17, 23, 26, 27, 28, 29, 32, 33, 34, 35, 38, 39, 44, 45, 46, 47, 50, 51, 52, 53, 56, 57, 58, 59, 62, 65, 68, 69, 70, 71, 74, 75, 76, 77, 82, 83, 86, 87, 88, 89, 92, 93, 94, 95, 98, 99, 104, 107, 112, 113, 116, 117, 118, 119, 122, 123, 124]

cp's OEIS Frontend

A140769 Numbers n such that consecutive Mersenne numbers A000225(n-1) = M(n-1) = 2^(n-1) - 1 and A000225(n) = M(n) = 2^n - 1 are both squarefree.

Table of values

List of values

n	a(n)
1	2
2	3
3	4
4	5
5	8
6	9
7	10
8	11
9	14
10	15
11	16
12	17
13	23
14	26
15	27
16	28
17	29
18	32
19	33
20	34
21	35
22	38
23	39
24	44
25	45
26	46
27	47
28	50
29	51
30	52
31	53
32	56
33	57
34	58
35	59
36	62
37	65
38	68
39	69
40	70
41	71
42	74
43	75
44	76
45	77
46	82
47	83
48	86
49	87
50	88
51	89
52	92
53	93
54	94
55	95
56	98
57	99
58	104
59	107
60	112
61	113
62	116
63	117
64	118
65	119
66	122
67	123
68	124

n	a(n)
1	2
2	3
3	4
4	5
5	8
6	9
7	10
8	11
9	14
10	15
11	16
12	17
13	23
14	26
15	27
16	28
17	29
18	32
19	33
20	34
21	35
22	38
23	39
24	44
25	45
26	46
27	47
28	50
29	51
30	52
31	53
32	56
33	57
34	58
35	59
36	62
37	65
38	68
39	69
40	70
41	71
42	74
43	75
44	76
45	77
46	82
47	83
48	86
49	87
50	88
51	89
52	92
53	93
54	94
55	95
56	98
57	99
58	104
59	107
60	112
61	113
62	116
63	117
64	118
65	119
66	122
67	123
68	124

n	a(n)
1	2
2	3
3	4
4	5
5	8
6	9
7	10
8	11
9	14
10	15
11	16
12	17
13	23
14	26
15	27
16	28
17	29
18	32
19	33
20	34
21	35
22	38
23	39
24	44
25	45
26	46
27	47
28	50
29	51
30	52
31	53
32	56
33	57
34	58
35	59
36	62
37	65
38	68
39	69
40	70
41	71
42	74
43	75
44	76
45	77
46	82
47	83
48	86
49	87
50	88
51	89
52	92
53	93
54	94
55	95
56	98
57	99
58	104
59	107
60	112
61	113
62	116
63	117
64	118
65	119
66	122
67	123
68	124