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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.

A320645 Number of chiral pairs of color patterns (set partitions) in a cycle of length n using exactly 5 colors (subsets).

Table of values

n a(n)
1 0
2 0
3 0
4 0
5 0
6 0
7 4
8 51
9 339
10 2010
11 10900
12 56700
13 286888
14 1426542
15 7014746
16 34229050
17 166197824
18 804243285
19 3883608940
20 18729354638
21 90266471623
22 434946282498
23 2096010533584
24 10104160993993
25 48733654211358
26 235195966291020
27 1135892493220025
28 5490005931157446
29 26555178320890184
30 128550000630553133
31 622790399873432344
32 3019641804537586657

List of values

[0, 0, 0, 0, 0, 0, 4, 51, 339, 2010, 10900, 56700, 286888, 1426542, 7014746, 34229050, 166197824, 804243285, 3883608940, 18729354638, 90266471623, 434946282498, 2096010533584, 10104160993993, 48733654211358, 235195966291020, 1135892493220025, 5490005931157446, 26555178320890184, 128550000630553133, 622790399873432344, 3019641804537586657]

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

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