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.

A322751 Number of directed graphs of 2*n vertices each having an in-degree and out-degree of 1 such that the graph specifies a pairwise connected gift exchange.

Table of values

n a(n)
0 1
1 0
2 4
3 80
4 4704
5 436992
6 58897920
7 10880501760
8 2640513576960
9 814928486400000
10 311763576754667520
11 144816978675459686400
12 80294888451877031116800
13 52385405443881146567884800
14 39727727942688305214337843200
15 34656123210118214086941474816000

List of values

[1, 0, 4, 80, 4704, 436992, 58897920, 10880501760, 2640513576960, 814928486400000, 311763576754667520, 144816978675459686400, 80294888451877031116800, 52385405443881146567884800, 39727727942688305214337843200, 34656123210118214086941474816000]

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

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