A284631 - cp's OEIS frontend

A284631 a(n) = smallest odd k such that either k2^n - 1 or k2^n + 1 is prime.

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

[1, 1, 1, 1, 1, 3, 1, 1, 7, 5, 3, 3, 1, 5, 5, 1, 1, 3, 1, 7, 7, 25, 13, 39, 5, 7, 15, 13, 7, 3, 1, 5, 9, 3, 25, 3, 15, 3, 5, 27, 3, 9, 3, 15, 7, 19, 27, 5, 19, 7, 17, 7, 51, 5, 3, 27, 29, 77, 27, 17, 1, 53, 9, 3, 9, 3, 9, 31, 23, 27, 39, 5, 15, 21, 5, 3, 29]

cp's OEIS Frontend

A284631 a(n) = smallest odd k such that either k2^n - 1 or k2^n + 1 is prime.

Table of values

List of values

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

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

cp's OEIS Frontend

A284631 a(n) = smallest odd k such that either k*2^n - 1 or k*2^n + 1 is prime.

Table of values

List of values

A284631 a(n) = smallest odd k such that either k2^n - 1 or k2^n + 1 is prime.

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