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.

A306878 Number of 0 < k < n such that n-k and n+k are both nonprimes.

Table of values

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

List of values

[0, 0, 0, 0, 2, 1, 2, 3, 3, 3, 5, 5, 6, 6, 7, 6, 9, 10, 8, 10, 11, 10, 12, 13, 13, 13, 15, 14, 16, 18, 15, 18, 20, 16, 20, 21, 20, 21, 24, 21, 23, 26, 24, 24, 29, 25, 27, 30, 26, 30, 32, 29, 31, 33, 31, 33, 36, 33, 34, 41, 34, 36, 42, 35, 40, 42, 40, 40, 43, 42, 44, 48, 44, 44]

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