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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.

A345764 Number the tiles of a regular hexagonal tiling from 0 in a spiral. Consider perpendicular axes, X and Y, through the center of tile 0, one of which passes through the center of tile 1. Define a set of equivalence classes of tiles with respect to reflections about X and Y. a(n) is the smallest number of a tile in the same equivalence class as tile n.

Table of values

n a(n)
0 0
1 1
2 2
3 2
4 1
5 2
6 2
7 7
8 8
9 7
10 10
11 11
12 10
13 7
14 8
15 7
16 10
17 11
18 10
19 19
20 20
21 21
22 20
23 19
24 24
25 25
26 25
27 24
28 19
29 20
30 21
31 20
32 19
33 24
34 25
35 25
36 24
37 37
38 38
39 39
40 40
41 39
42 38
43 37
44 44
45 45
46 46
47 45
48 44
49 37
50 38
51 39
52 40
53 39
54 38
55 37
56 44
57 45
58 46
59 45
60 44
61 61
62 62
63 63
64 64
65 65
66 64
67 63
68 62
69 61

List of values

[0, 1, 2, 2, 1, 2, 2, 7, 8, 7, 10, 11, 10, 7, 8, 7, 10, 11, 10, 19, 20, 21, 20, 19, 24, 25, 25, 24, 19, 20, 21, 20, 19, 24, 25, 25, 24, 37, 38, 39, 40, 39, 38, 37, 44, 45, 46, 45, 44, 37, 38, 39, 40, 39, 38, 37, 44, 45, 46, 45, 44, 61, 62, 63, 64, 65, 64, 63, 62, 61]

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