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.

A257405 For n=1 or prime, a(n)=n; otherwise, a(n) is the smallest number not already used which shares a factor with a(n-1).

Table of values

n a(n)
1 1
2 2
3 3
4 6
5 5
6 10
7 7
8 14
9 4
10 8
11 11
12 22
13 13
14 26
15 12
16 9
17 17
18 34
19 19
20 38
21 16
22 18
23 23
24 46
25 20
26 15
27 21
28 24
29 29
30 58
31 31
32 62
33 28
34 30
35 25
36 35
37 37
38 74
39 32
40 36
41 41
42 82
43 43
44 86
45 40
46 42
47 47
48 94
49 44
50 33
51 27
52 39
53 53
54 106
55 48
56 45
57 50
58 52
59 59
60 118
61 61
62 122
63 54
64 51
65 57
66 60
67 67

List of values

[1, 2, 3, 6, 5, 10, 7, 14, 4, 8, 11, 22, 13, 26, 12, 9, 17, 34, 19, 38, 16, 18, 23, 46, 20, 15, 21, 24, 29, 58, 31, 62, 28, 30, 25, 35, 37, 74, 32, 36, 41, 82, 43, 86, 40, 42, 47, 94, 44, 33, 27, 39, 53, 106, 48, 45, 50, 52, 59, 118, 61, 122, 54, 51, 57, 60, 67]

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

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