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.

A335661 The squares visited on a square (Ulam) spiral, with a(1) = 1 and a(2) = 2, when stepping to the closest unvisited square containing a number that shares a common divisor > 1 with the number in the current square. If two or more such squares are the same distance from the current square then the one with the smallest number is chosen.

Table of values

n a(n)
1 1
2 2
3 4
4 6
5 8
6 22
7 20
8 40
9 18
10 39
11 69
12 105
13 150
14 104
15 66
16 38
17 36
18 63
19 98
20 62
21 34
22 14
23 12
24 3
25 15
26 5
27 35
28 60
29 33
30 30
31 55
32 88
33 54
34 87
35 129
36 177
37 234
38 299
39 455
40 375
41 456
42 374
43 300
44 235
45 130
46 90
47 57
48 93
49 135
50 186
51 134
52 92
53 58
54 32
55 56
56 91
57 133
58 182
59 132
60 180
61 237

List of values

[1, 2, 4, 6, 8, 22, 20, 40, 18, 39, 69, 105, 150, 104, 66, 38, 36, 63, 98, 62, 34, 14, 12, 3, 15, 5, 35, 60, 33, 30, 55, 88, 54, 87, 129, 177, 234, 299, 455, 375, 456, 374, 300, 235, 130, 90, 57, 93, 135, 186, 134, 92, 58, 32, 56, 91, 133, 182, 132, 180, 237]

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

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