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.

A002031 Number of labeled connected digraphs on n nodes where every node has indegree 0 or outdegree 0 and no isolated nodes.

Table of values

n a(n)
2 2
3 6
4 38
5 390
6 6062
7 134526
8 4172198
9 178449270
10 10508108222
11 853219059726
12 95965963939958
13 15015789392011590
14 3282145108526132942
15 1005193051984479922206
16 432437051675617901246918
17 261774334771663762228012950
18 223306437526333657726283273822

List of values

[2, 6, 38, 390, 6062, 134526, 4172198, 178449270, 10508108222, 853219059726, 95965963939958, 15015789392011590, 3282145108526132942, 1005193051984479922206, 432437051675617901246918, 261774334771663762228012950, 223306437526333657726283273822]

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

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