A139457 - cp's OEIS frontend

A139457 a(n)= smallest m such that primorial(n)/2 + 2^m is prime.

n	a(n)
1	0
2	1
3	1
4	1
5	3
6	1
7	2
8	4
9	3
10	1
11	1
12	1
13	4
14	10
15	1
16	11
17	1
18	2
19	11
20	14
21	2
22	8
23	7
24	3
25	4
26	4
27	26
28	21
29	1
30	4
31	15
32	10
33	8
34	4
35	16
36	29
37	10
38	3
39	51
40	17
41	5
42	12
43	12
44	48
45	13
46	45
47	12
48	1
49	20
50	17
51	65
52	12
53	8
54	95
55	5
56	12
57	11
58	8
59	110
60	38
61	28
62	8
63	1
64	23
65	13
66	5
67	7
68	11
69	21
70	2
71	20
72	32
73	9
74	66
75	4
76	2
77	1
78	20
79	34
80	97
81	28
82	80

[0, 1, 1, 1, 3, 1, 2, 4, 3, 1, 1, 1, 4, 10, 1, 11, 1, 2, 11, 14, 2, 8, 7, 3, 4, 4, 26, 21, 1, 4, 15, 10, 8, 4, 16, 29, 10, 3, 51, 17, 5, 12, 12, 48, 13, 45, 12, 1, 20, 17, 65, 12, 8, 95, 5, 12, 11, 8, 110, 38, 28, 8, 1, 23, 13, 5, 7, 11, 21, 2, 20, 32, 9, 66, 4, 2, 1, 20, 34, 97, 28, 80]

cp's OEIS Frontend

A139457 a(n)= smallest m such that primorial(n)/2 + 2^m is prime.

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	1
5	3
6	1
7	2
8	4
9	3
10	1
11	1
12	1
13	4
14	10
15	1
16	11
17	1
18	2
19	11
20	14
21	2
22	8
23	7
24	3
25	4
26	4
27	26
28	21
29	1
30	4
31	15
32	10
33	8
34	4
35	16
36	29
37	10
38	3
39	51
40	17
41	5
42	12
43	12
44	48
45	13
46	45
47	12
48	1
49	20
50	17
51	65
52	12
53	8
54	95
55	5
56	12
57	11
58	8
59	110
60	38
61	28
62	8
63	1
64	23
65	13
66	5
67	7
68	11
69	21
70	2
71	20
72	32
73	9
74	66
75	4
76	2
77	1
78	20
79	34
80	97
81	28
82	80

n	a(n)
1	0
2	1
3	1
4	1
5	3
6	1
7	2
8	4
9	3
10	1
11	1
12	1
13	4
14	10
15	1
16	11
17	1
18	2
19	11
20	14
21	2
22	8
23	7
24	3
25	4
26	4
27	26
28	21
29	1
30	4
31	15
32	10
33	8
34	4
35	16
36	29
37	10
38	3
39	51
40	17
41	5
42	12
43	12
44	48
45	13
46	45
47	12
48	1
49	20
50	17
51	65
52	12
53	8
54	95
55	5
56	12
57	11
58	8
59	110
60	38
61	28
62	8
63	1
64	23
65	13
66	5
67	7
68	11
69	21
70	2
71	20
72	32
73	9
74	66
75	4
76	2
77	1
78	20
79	34
80	97
81	28
82	80

n	a(n)
1	0
2	1
3	1
4	1
5	3
6	1
7	2
8	4
9	3
10	1
11	1
12	1
13	4
14	10
15	1
16	11
17	1
18	2
19	11
20	14
21	2
22	8
23	7
24	3
25	4
26	4
27	26
28	21
29	1
30	4
31	15
32	10
33	8
34	4
35	16
36	29
37	10
38	3
39	51
40	17
41	5
42	12
43	12
44	48
45	13
46	45
47	12
48	1
49	20
50	17
51	65
52	12
53	8
54	95
55	5
56	12
57	11
58	8
59	110
60	38
61	28
62	8
63	1
64	23
65	13
66	5
67	7
68	11
69	21
70	2
71	20
72	32
73	9
74	66
75	4
76	2
77	1
78	20
79	34
80	97
81	28
82	80