A040076 - cp's OEIS frontend

A040076 Smallest m >= 0 such that n*2^m + 1 is prime, or -1 if no such m exists.

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	0
7	2
8	1
9	1
10	0
11	1
12	0
13	2
14	1
15	1
16	0
17	3
18	0
19	6
20	1
21	1
22	0
23	1
24	2
25	2
26	1
27	2
28	0
29	1
30	0
31	8
32	3
33	1
34	2
35	1
36	0
37	2
38	5
39	1
40	0
41	1
42	0
43	2
44	1
45	2
46	0
47	583
48	1
49	2
50	1
51	1
52	0
53	1
54	1
55	4
56	1
57	2
58	0
59	5
60	0
61	4
62	7
63	1
64	2
65	1
66	0
67	2
68	1
69	1
70	0
71	3
72	0
73	2
74	1
75	1
76	4
77	3
78	0
79	2
80	3
81	1
82	0
83	1
84	2
85	4
86	1
87	2
88	0
89	1
90	1
91	8
92	7
93	2
94	582
95	1
96	0
97	2
98	1
99	1
100	0
101	3
102	0

[0, 0, 1, 0, 1, 0, 2, 1, 1, 0, 1, 0, 2, 1, 1, 0, 3, 0, 6, 1, 1, 0, 1, 2, 2, 1, 2, 0, 1, 0, 8, 3, 1, 2, 1, 0, 2, 5, 1, 0, 1, 0, 2, 1, 2, 0, 583, 1, 2, 1, 1, 0, 1, 1, 4, 1, 2, 0, 5, 0, 4, 7, 1, 2, 1, 0, 2, 1, 1, 0, 3, 0, 2, 1, 1, 4, 3, 0, 2, 3, 1, 0, 1, 2, 4, 1, 2, 0, 1, 1, 8, 7, 2, 582, 1, 0, 2, 1, 1, 0, 3, 0]

cp's OEIS Frontend

A040076 Smallest m >= 0 such that n*2^m + 1 is prime, or -1 if no such m exists.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	0
7	2
8	1
9	1
10	0
11	1
12	0
13	2
14	1
15	1
16	0
17	3
18	0
19	6
20	1
21	1
22	0
23	1
24	2
25	2
26	1
27	2
28	0
29	1
30	0
31	8
32	3
33	1
34	2
35	1
36	0
37	2
38	5
39	1
40	0
41	1
42	0
43	2
44	1
45	2
46	0
47	583
48	1
49	2
50	1
51	1
52	0
53	1
54	1
55	4
56	1
57	2
58	0
59	5
60	0
61	4
62	7
63	1
64	2
65	1
66	0
67	2
68	1
69	1
70	0
71	3
72	0
73	2
74	1
75	1
76	4
77	3
78	0
79	2
80	3
81	1
82	0
83	1
84	2
85	4
86	1
87	2
88	0
89	1
90	1
91	8
92	7
93	2
94	582
95	1
96	0
97	2
98	1
99	1
100	0
101	3
102	0

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	0
7	2
8	1
9	1
10	0
11	1
12	0
13	2
14	1
15	1
16	0
17	3
18	0
19	6
20	1
21	1
22	0
23	1
24	2
25	2
26	1
27	2
28	0
29	1
30	0
31	8
32	3
33	1
34	2
35	1
36	0
37	2
38	5
39	1
40	0
41	1
42	0
43	2
44	1
45	2
46	0
47	583
48	1
49	2
50	1
51	1
52	0
53	1
54	1
55	4
56	1
57	2
58	0
59	5
60	0
61	4
62	7
63	1
64	2
65	1
66	0
67	2
68	1
69	1
70	0
71	3
72	0
73	2
74	1
75	1
76	4
77	3
78	0
79	2
80	3
81	1
82	0
83	1
84	2
85	4
86	1
87	2
88	0
89	1
90	1
91	8
92	7
93	2
94	582
95	1
96	0
97	2
98	1
99	1
100	0
101	3
102	0

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	0
7	2
8	1
9	1
10	0
11	1
12	0
13	2
14	1
15	1
16	0
17	3
18	0
19	6
20	1
21	1
22	0
23	1
24	2
25	2
26	1
27	2
28	0
29	1
30	0
31	8
32	3
33	1
34	2
35	1
36	0
37	2
38	5
39	1
40	0
41	1
42	0
43	2
44	1
45	2
46	0
47	583
48	1
49	2
50	1
51	1
52	0
53	1
54	1
55	4
56	1
57	2
58	0
59	5
60	0
61	4
62	7
63	1
64	2
65	1
66	0
67	2
68	1
69	1
70	0
71	3
72	0
73	2
74	1
75	1
76	4
77	3
78	0
79	2
80	3
81	1
82	0
83	1
84	2
85	4
86	1
87	2
88	0
89	1
90	1
91	8
92	7
93	2
94	582
95	1
96	0
97	2
98	1
99	1
100	0
101	3
102	0