A127586 - cp's OEIS frontend

A127586 Smallest strictly positive integer k such that (k+1)*2^n-1 is prime.

n	a(n)
0	2
1	1
2	1
3	2
4	1
5	3
6	1
7	2
8	4
9	6
10	4
11	2
12	1
13	8
14	4
15	3
16	1
17	3
18	1
19	27
20	13
21	6
22	25
23	12
24	38
25	21
26	10
27	15
28	7
29	3
30	1
31	9
32	4
33	5
34	2
35	23
36	11
37	5
38	2
39	24
40	23
41	11
42	5
43	2
44	13
45	6
46	19
47	9
48	4
49	18
50	10

[2, 1, 1, 2, 1, 3, 1, 2, 4, 6, 4, 2, 1, 8, 4, 3, 1, 3, 1, 27, 13, 6, 25, 12, 38, 21, 10, 15, 7, 3, 1, 9, 4, 5, 2, 23, 11, 5, 2, 24, 23, 11, 5, 2, 13, 6, 19, 9, 4, 18, 10]

cp's OEIS Frontend

A127586 Smallest strictly positive integer k such that (k+1)*2^n-1 is prime.

Table of values

List of values

n	a(n)
0	2
1	1
2	1
3	2
4	1
5	3
6	1
7	2
8	4
9	6
10	4
11	2
12	1
13	8
14	4
15	3
16	1
17	3
18	1
19	27
20	13
21	6
22	25
23	12
24	38
25	21
26	10
27	15
28	7
29	3
30	1
31	9
32	4
33	5
34	2
35	23
36	11
37	5
38	2
39	24
40	23
41	11
42	5
43	2
44	13
45	6
46	19
47	9
48	4
49	18
50	10

n	a(n)
0	2
1	1
2	1
3	2
4	1
5	3
6	1
7	2
8	4
9	6
10	4
11	2
12	1
13	8
14	4
15	3
16	1
17	3
18	1
19	27
20	13
21	6
22	25
23	12
24	38
25	21
26	10
27	15
28	7
29	3
30	1
31	9
32	4
33	5
34	2
35	23
36	11
37	5
38	2
39	24
40	23
41	11
42	5
43	2
44	13
45	6
46	19
47	9
48	4
49	18
50	10

n	a(n)
0	2
1	1
2	1
3	2
4	1
5	3
6	1
7	2
8	4
9	6
10	4
11	2
12	1
13	8
14	4
15	3
16	1
17	3
18	1
19	27
20	13
21	6
22	25
23	12
24	38
25	21
26	10
27	15
28	7
29	3
30	1
31	9
32	4
33	5
34	2
35	23
36	11
37	5
38	2
39	24
40	23
41	11
42	5
43	2
44	13
45	6
46	19
47	9
48	4
49	18
50	10