cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A237769 Number of primes p < n with pi(n-p) - 1 and pi(n-p) + 1 both prime, where pi(.) is given by A000720.

Table of values

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

List of values

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

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.