A238878 - cp's OEIS frontend

A238878 a(n) = |{0 < k <= n: prime(prime(k)) - prime(k) + 1 and prime(prime(kn)) - prime(kn) + 1 are both prime}|.

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

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

cp's OEIS Frontend

A238878 a(n) = |{0 < k <= n: prime(prime(k)) - prime(k) + 1 and prime(prime(kn)) - prime(kn) + 1 are both prime}|.

Table of values

List of values

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

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

cp's OEIS Frontend

A238878 a(n) = |{0 < k <= n: prime(prime(k)) - prime(k) + 1 and prime(prime(k*n)) - prime(k*n) + 1 are both prime}|.

Table of values

List of values

A238878 a(n) = |{0 < k <= n: prime(prime(k)) - prime(k) + 1 and prime(prime(kn)) - prime(kn) + 1 are both prime}|.

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