A238890 - cp's OEIS frontend

A238890 a(n) = |{0 < k <= n: prime(kn) - pi(kn) is prime}|, where pi(x) denotes the number of primes not exceeding x.

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

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

cp's OEIS Frontend

A238890 a(n) = |{0 < k <= n: prime(kn) - pi(kn) is prime}|, where pi(x) denotes the number of primes not exceeding x.

Table of values

List of values

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

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

cp's OEIS Frontend

A238890 a(n) = |{0 < k <= n: prime(k*n) - pi(k*n) is prime}|, where pi(x) denotes the number of primes not exceeding x.

Table of values

List of values

A238890 a(n) = |{0 < k <= n: prime(kn) - pi(kn) is prime}|, where pi(x) denotes the number of primes not exceeding x.

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