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.

A257112 Arrange numbers in a clockwise spiral with initial terms a(1)=1, a(2)=2, a(4)=4, a(6)=6, a(8)=8, a(11)=3, a(15)=5, a(19)=7, a(23)=9; thereafter each number is relatively prime to all of its four (N,S,E,W) neighbors, but shares a factor with each of its (N,S,E,W) neighbors at distance 2 and also satisfies an additional condition stated in the comments.

Table of values

n a(n)
1 1
2 2
3 11
4 4
5 55
6 6
7 25
8 8
9 165
10 14
11 3
12 16
13 15
14 26
15 5
16 12
17 35
18 18
19 7
20 22
21 21
22 32
23 9
24 28
25 27
26 10
27 33
28 20
29 77
30 34
31 49
32 38
33 231
34 46
35 121
36 24
37 143
38 36
39 65
40 44
41 45
42 52
43 51
44 58
45 75
46 56
47 39
48 40
49 57
50 50
51 63
52 62
53 69
54 64
55 81
56 68
57 87
58 17
59 93
60 136
61 105
62 74
63 85
64 42
65 95
66 48
67 115
68 54
69 161

List of values

[1, 2, 11, 4, 55, 6, 25, 8, 165, 14, 3, 16, 15, 26, 5, 12, 35, 18, 7, 22, 21, 32, 9, 28, 27, 10, 33, 20, 77, 34, 49, 38, 231, 46, 121, 24, 143, 36, 65, 44, 45, 52, 51, 58, 75, 56, 39, 40, 57, 50, 63, 62, 69, 64, 81, 68, 87, 17, 93, 136, 105, 74, 85, 42, 95, 48, 115, 54, 161]

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

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