A078680 - cp's OEIS frontend

A078680 Smallest m > 0 such that n*2^m + 1 is prime, or 0 if no such m exists.

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

[1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 3, 2, 1, 1, 4, 3, 1, 6, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 8, 3, 1, 2, 1, 1, 2, 5, 1, 4, 1, 3, 2, 1, 2, 8, 583, 1, 2, 1, 1, 6, 1, 1, 4, 1, 2, 2, 5, 2, 4, 7, 1, 2, 1, 5, 2, 1, 1, 2, 3, 3, 2, 1, 1, 4, 3, 1, 2, 3, 1, 10, 1, 2, 4, 1, 2, 2, 1, 1, 8, 7, 2, 582, 1, 1, 2, 1, 1, 2, 3, 2]

cp's OEIS Frontend

A078680 Smallest m > 0 such that n*2^m + 1 is prime, or 0 if no such m exists.

Table of values

List of values

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

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

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