A194636 - cp's OEIS frontend

A194636 Least k >= 0 such that (2n-1)2^k - 1 or (2n-1)2^k + 1 is prime, or -1 if no such value exists.

n	a(n)
1	0
2	0
3	1
4	1
5	1
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	2
23	1
24	4
25	1
26	1
27	1
28	1
29	1
30	5
31	3
32	1
33	1
34	2
35	1
36	2
37	2
38	1
39	2
40	1
41	1
42	1
43	4
44	1
45	1
46	1
47	2
48	1
49	1
50	1
51	3
52	3
53	1
54	3
55	6
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	1
69	2
70	1
71	1
72	2
73	5
74	1
75	3
76	4
77	1
78	1
79	1
80	1
81	2
82	2
83	1
84	4
85	1
86	2

[0, 0, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 4, 1, 1, 1, 1, 1, 5, 3, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 3, 3, 1, 3, 6, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 3, 1, 2, 1, 1, 2, 5, 1, 3, 4, 1, 1, 1, 1, 2, 2, 1, 4, 1, 2]

cp's OEIS Frontend

A194636 Least k >= 0 such that (2n-1)2^k - 1 or (2n-1)2^k + 1 is prime, or -1 if no such value exists.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	1
5	1
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	2
23	1
24	4
25	1
26	1
27	1
28	1
29	1
30	5
31	3
32	1
33	1
34	2
35	1
36	2
37	2
38	1
39	2
40	1
41	1
42	1
43	4
44	1
45	1
46	1
47	2
48	1
49	1
50	1
51	3
52	3
53	1
54	3
55	6
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	1
69	2
70	1
71	1
72	2
73	5
74	1
75	3
76	4
77	1
78	1
79	1
80	1
81	2
82	2
83	1
84	4
85	1
86	2

n	a(n)
1	0
2	0
3	1
4	1
5	1
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	2
23	1
24	4
25	1
26	1
27	1
28	1
29	1
30	5
31	3
32	1
33	1
34	2
35	1
36	2
37	2
38	1
39	2
40	1
41	1
42	1
43	4
44	1
45	1
46	1
47	2
48	1
49	1
50	1
51	3
52	3
53	1
54	3
55	6
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	1
69	2
70	1
71	1
72	2
73	5
74	1
75	3
76	4
77	1
78	1
79	1
80	1
81	2
82	2
83	1
84	4
85	1
86	2

cp's OEIS Frontend

A194636 Least k >= 0 such that (2*n-1)*2^k - 1 or (2*n-1)*2^k + 1 is prime, or -1 if no such value exists.

Table of values

List of values

A194636 Least k >= 0 such that (2n-1)2^k - 1 or (2n-1)2^k + 1 is prime, or -1 if no such value exists.

n	a(n)
1	0
2	0
3	1
4	1
5	1
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	2
23	1
24	4
25	1
26	1
27	1
28	1
29	1
30	5
31	3
32	1
33	1
34	2
35	1
36	2
37	2
38	1
39	2
40	1
41	1
42	1
43	4
44	1
45	1
46	1
47	2
48	1
49	1
50	1
51	3
52	3
53	1
54	3
55	6
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	1
69	2
70	1
71	1
72	2
73	5
74	1
75	3
76	4
77	1
78	1
79	1
80	1
81	2
82	2
83	1
84	4
85	1
86	2