A237582 - cp's OEIS frontend

A237582 a(n) = |{0 < k < n: pi(n + k^2) is prime}|, where pi(.) is given by A000720.

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

[0, 1, 1, 1, 1, 1, 2, 3, 2, 3, 4, 1, 2, 2, 3, 6, 6, 5, 5, 5, 5, 6, 7, 7, 6, 5, 6, 5, 6, 7, 8, 9, 8, 10, 9, 8, 6, 6, 6, 6, 7, 9, 9, 10, 11, 11, 13, 11, 9, 9, 10, 10, 8, 6, 6, 5, 4, 8, 9, 10, 12, 11, 14, 15, 15, 15, 12, 14, 15, 17, 16, 13, 11, 11, 13, 16, 18, 24, 25, 20]

cp's OEIS Frontend

A237582 a(n) = |{0 < k < n: pi(n + k^2) is prime}|, where pi(.) is given by A000720.

Table of values

List of values

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

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

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