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.

A320644 Number of chiral pairs of color patterns (set partitions) in a cycle of length n using exactly 4 colors (subsets).

Table of values

n a(n)
1 0
2 0
3 0
4 0
5 0
6 2
7 17
8 84
9 388
10 1586
11 6405
12 24927
13 96404
14 368641
15 1407515
16 5357974
17 20403120
18 77699323
19 296229485
20 1130614092
21 4321324766
22 16539645539
23 63397442097
24 243352167691
25 935420468092
26 3600493932070
27 13876442107403
28 53546144395718
29 206864753332164
30 800067806813323
31 3097590602034137
32 12004772596768984
33 46568647645538594
34 180809553280920680

List of values

[0, 0, 0, 0, 0, 2, 17, 84, 388, 1586, 6405, 24927, 96404, 368641, 1407515, 5357974, 20403120, 77699323, 296229485, 1130614092, 4321324766, 16539645539, 63397442097, 243352167691, 935420468092, 3600493932070, 13876442107403, 53546144395718, 206864753332164, 800067806813323, 3097590602034137, 12004772596768984, 46568647645538594, 180809553280920680]

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

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