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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.

A001373 Number of functional digraphs (digraphs of functions on n nodes where every node has outdegree 1 and loops of length 1 are forbidden).

Table of values

n a(n)
0 1
1 0
2 1
3 2
4 6
5 13
6 40
7 100
8 291
9 797
10 2273
11 6389
12 18264
13 51916
14 148666
15 425529
16 1221900
17 3511507
18 10111043
19 29142941
20 84112009
21 243000149
22 702758065
23 2034150215
24 5892907566
25 17084615940
26 49567063847
27 143902155133
28 418032946298
29 1215076634226
30 3533715961160
31 10282042126394
32 29931877173282
33 87173224346464
34 253989569994664

List of values

[1, 0, 1, 2, 6, 13, 40, 100, 291, 797, 2273, 6389, 18264, 51916, 148666, 425529, 1221900, 3511507, 10111043, 29142941, 84112009, 243000149, 702758065, 2034150215, 5892907566, 17084615940, 49567063847, 143902155133, 418032946298, 1215076634226, 3533715961160, 10282042126394, 29931877173282, 87173224346464, 253989569994664]

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

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