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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.

A220638 Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly one king-move neighbor.

Table of values

n a(n)
0 1
1 1
2 10
3 369
4 92801
5 128171936
6 1040315976961
7 48590896359378961
8 13140746227808545282304
9 20540255065209806005525289313
10 185661218973084382181156348510614065
11 9703072851259276652446200332793680010752000
12 2932144456272256572796083896528773941130429279461761

List of values

[1, 1, 10, 369, 92801, 128171936, 1040315976961, 48590896359378961, 13140746227808545282304, 20540255065209806005525289313, 185661218973084382181156348510614065, 9703072851259276652446200332793680010752000, 2932144456272256572796083896528773941130429279461761]

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

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