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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.

A227455 Sequence defined recursively: 1 is in the sequence, and k > 1 is in the sequence iff for some prime divisor p of k, p-1 is not in the sequence.

Table of values

n a(n)
1 1
2 3
3 5
4 6
5 9
6 10
7 12
8 15
9 17
10 18
11 20
12 21
13 23
14 24
15 25
16 27
17 29
18 30
19 33
20 34
21 35
22 36
23 39
24 40
25 42
26 45
27 46
28 48
29 50
30 51
31 53
32 54
33 55
34 57
35 58
36 60
37 63
38 65
39 66
40 68
41 69
42 70
43 72
44 75
45 78
46 80
47 81
48 83
49 84
50 85
51 87
52 89
53 90
54 92
55 93
56 95
57 96
58 99
59 100
60 102
61 105
62 106
63 108
64 110

List of values

[1, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 21, 23, 24, 25, 27, 29, 30, 33, 34, 35, 36, 39, 40, 42, 45, 46, 48, 50, 51, 53, 54, 55, 57, 58, 60, 63, 65, 66, 68, 69, 70, 72, 75, 78, 80, 81, 83, 84, 85, 87, 89, 90, 92, 93, 95, 96, 99, 100, 102, 105, 106, 108, 110]

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

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