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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.

A320527 Number of chiral pairs of color patterns (set partitions) in a row of length n using exactly 4 colors (subsets).

Table of values

n a(n)
1 0
2 0
3 0
4 0
5 4
6 28
7 167
8 824
9 3840
10 16920
11 72655
12 305140
13 1265264
14 5193188
15 21173607
16 85887984
17 347150080
18 1399355440
19 5629755935
20 22615859180
21 90754215024
22 363888497148
23 1458169977847
24 5840524999144
25 23385639542720
26 93613165023560
27 374664497695215
28 1499293455643620
29 5999080285068784
30 24002040333605908

List of values

[0, 0, 0, 0, 4, 28, 167, 824, 3840, 16920, 72655, 305140, 1265264, 5193188, 21173607, 85887984, 347150080, 1399355440, 5629755935, 22615859180, 90754215024, 363888497148, 1458169977847, 5840524999144, 23385639542720, 93613165023560, 374664497695215, 1499293455643620, 5999080285068784, 24002040333605908]

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

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