A330558 - cp's OEIS frontend

A330558 a(n) = number of primes p <= 2*n+1 with Delta(p) == 0 mod 4, where Delta(p) = nextprime(p) - p.

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

[0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12]

cp's OEIS Frontend

A330558 a(n) = number of primes p <= 2*n+1 with Delta(p) == 0 mod 4, where Delta(p) = nextprime(p) - p.

Table of values

List of values

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

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

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