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.

A099049 Numbers n such that n-1 and n+1 are both prime or both composite.

Table of values

n a(n)
1 4
2 5
3 6
4 7
5 9
6 11
7 12
8 13
9 15
10 17
11 18
12 19
13 21
14 23
15 25
16 26
17 27
18 29
19 30
20 31
21 33
22 34
23 35
24 37
25 39
26 41
27 42
28 43
29 45
30 47
31 49
32 50
33 51
34 53
35 55
36 56
37 57
38 59
39 60
40 61
41 63
42 64
43 65
44 67
45 69
46 71
47 72
48 73
49 75
50 76
51 77
52 79
53 81
54 83
55 85
56 86
57 87
58 89
59 91
60 92
61 93
62 94
63 95
64 97
65 99
66 101
67 102
68 103
69 105
70 107

List of values

[4, 5, 6, 7, 9, 11, 12, 13, 15, 17, 18, 19, 21, 23, 25, 26, 27, 29, 30, 31, 33, 34, 35, 37, 39, 41, 42, 43, 45, 47, 49, 50, 51, 53, 55, 56, 57, 59, 60, 61, 63, 64, 65, 67, 69, 71, 72, 73, 75, 76, 77, 79, 81, 83, 85, 86, 87, 89, 91, 92, 93, 94, 95, 97, 99, 101, 102, 103, 105, 107]

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

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