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.

A270174 a(n) is the number of different ways to seat a set of n married male-female couples at a straight table so that men and women alternate and every man is separated by at least two men from his wife.

Table of values

n a(n)
1 0
2 0
3 0
4 0
5 240
6 8640
7 584640
8 40239360
9 3493808640
10 364941158400
11 45683021260800
12 6754660222464000
13 1166167699041945600
14 232618987254682828800
15 53114643986227439616000
16 13768242163527512973312000
17 4021980517038414919532544000
18 1315337131173516220415213568000

List of values

[0, 0, 0, 0, 240, 8640, 584640, 40239360, 3493808640, 364941158400, 45683021260800, 6754660222464000, 1166167699041945600, 232618987254682828800, 53114643986227439616000, 13768242163527512973312000, 4021980517038414919532544000, 1315337131173516220415213568000]

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

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