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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.

A055973 Number of unlabeled digraphs with loops (relations) on n nodes and with an even number of arcs.

Table of values

n a(n)
0 1
1 1
2 6
3 52
4 1540
5 145984
6 48467296
7 56141454464
8 229148555640864
9 3333310786076963968
10 174695272746896566439424
11 33301710992539090379269318144
12 23278728241293494584257987458067456
13 60084295633556503802059558812644803074048
14 576025077880237078776946976495257043823396069376

List of values

[1, 1, 6, 52, 1540, 145984, 48467296, 56141454464, 229148555640864, 3333310786076963968, 174695272746896566439424, 33301710992539090379269318144, 23278728241293494584257987458067456, 60084295633556503802059558812644803074048, 576025077880237078776946976495257043823396069376]

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

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