A232068 - cp's OEIS frontend

A232068 Least k such that prime(n) + 2^(k+L) is a prime, where L is the length of binary representation of prime(n): L = A070939(A000040(n)). a(n)=-1 if no such k exists.

n	a(n)
2	0
3	0
4	1
5	1
6	0
7	8
8	1
9	2
10	0
11	7
12	0
13	5
14	0
15	203
16	1
17	3
18	2
19	3
20	0
21	3
22	3
23	0
24	2
25	1
26	0
27	1
28	2
29	7
30	0
31	1
32	1
33	5
34	2
35	1
36	8
37	2
38	0
39	501
40	3
41	1
42	8
43	3
44	0
45	1
46	2
47	0
48	0
49	1
50	22
51	3
52	1
53	4
54	5
55	0
56	2
57	4
58	11
59	1
60	6
61	1
62	2
63	5
64	0
65	3
66	0
67	7
68	1
69	0
70	1
71	18
72	8
73	3
74	13
75	5
76	6
77	2
78	3
79	34
80	1
81	2
82	3
83	4
84	19
85	5
86	6
87	4
88	1

[0, 0, 1, 1, 0, 8, 1, 2, 0, 7, 0, 5, 0, 203, 1, 3, 2, 3, 0, 3, 3, 0, 2, 1, 0, 1, 2, 7, 0, 1, 1, 5, 2, 1, 8, 2, 0, 501, 3, 1, 8, 3, 0, 1, 2, 0, 0, 1, 22, 3, 1, 4, 5, 0, 2, 4, 11, 1, 6, 1, 2, 5, 0, 3, 0, 7, 1, 0, 1, 18, 8, 3, 13, 5, 6, 2, 3, 34, 1, 2, 3, 4, 19, 5, 6, 4, 1]

cp's OEIS Frontend

A232068 Least k such that prime(n) + 2^(k+L) is a prime, where L is the length of binary representation of prime(n): L = A070939(A000040(n)). a(n)=-1 if no such k exists.

Table of values

List of values

n	a(n)
2	0
3	0
4	1
5	1
6	0
7	8
8	1
9	2
10	0
11	7
12	0
13	5
14	0
15	203
16	1
17	3
18	2
19	3
20	0
21	3
22	3
23	0
24	2
25	1
26	0
27	1
28	2
29	7
30	0
31	1
32	1
33	5
34	2
35	1
36	8
37	2
38	0
39	501
40	3
41	1
42	8
43	3
44	0
45	1
46	2
47	0
48	0
49	1
50	22
51	3
52	1
53	4
54	5
55	0
56	2
57	4
58	11
59	1
60	6
61	1
62	2
63	5
64	0
65	3
66	0
67	7
68	1
69	0
70	1
71	18
72	8
73	3
74	13
75	5
76	6
77	2
78	3
79	34
80	1
81	2
82	3
83	4
84	19
85	5
86	6
87	4
88	1

n	a(n)
2	0
3	0
4	1
5	1
6	0
7	8
8	1
9	2
10	0
11	7
12	0
13	5
14	0
15	203
16	1
17	3
18	2
19	3
20	0
21	3
22	3
23	0
24	2
25	1
26	0
27	1
28	2
29	7
30	0
31	1
32	1
33	5
34	2
35	1
36	8
37	2
38	0
39	501
40	3
41	1
42	8
43	3
44	0
45	1
46	2
47	0
48	0
49	1
50	22
51	3
52	1
53	4
54	5
55	0
56	2
57	4
58	11
59	1
60	6
61	1
62	2
63	5
64	0
65	3
66	0
67	7
68	1
69	0
70	1
71	18
72	8
73	3
74	13
75	5
76	6
77	2
78	3
79	34
80	1
81	2
82	3
83	4
84	19
85	5
86	6
87	4
88	1

n	a(n)
2	0
3	0
4	1
5	1
6	0
7	8
8	1
9	2
10	0
11	7
12	0
13	5
14	0
15	203
16	1
17	3
18	2
19	3
20	0
21	3
22	3
23	0
24	2
25	1
26	0
27	1
28	2
29	7
30	0
31	1
32	1
33	5
34	2
35	1
36	8
37	2
38	0
39	501
40	3
41	1
42	8
43	3
44	0
45	1
46	2
47	0
48	0
49	1
50	22
51	3
52	1
53	4
54	5
55	0
56	2
57	4
58	11
59	1
60	6
61	1
62	2
63	5
64	0
65	3
66	0
67	7
68	1
69	0
70	1
71	18
72	8
73	3
74	13
75	5
76	6
77	2
78	3
79	34
80	1
81	2
82	3
83	4
84	19
85	5
86	6
87	4
88	1