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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.

A251622 a(1) = 1; a(2) = 2; for n > 2, a(n) = smallest number not already used which shares a factor with a(n-1) or a(n-2).

Table of values

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

List of values

[1, 2, 4, 6, 3, 8, 9, 10, 5, 12, 14, 7, 16, 18, 15, 20, 21, 22, 11, 24, 26, 13, 28, 30, 25, 27, 33, 36, 32, 34, 17, 38, 19, 40, 35, 42, 39, 44, 45, 46, 23, 48, 50, 51, 52, 54, 56, 49, 58, 29, 60, 55, 57, 63, 66, 62, 31, 64, 68, 70, 65, 72, 69, 74, 37, 76, 78, 75, 80]

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