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.

A370464 Triangular array read by rows. T(n,k) is the number of binary relations R on [n] such that the unique idempotent in {R^i:i>=1} contains exactly k non-arcless strongly connected components, n>=0, 0<=k<=n.

Table of values

n a(n)
0 1
1 1
2 1
3 3
4 9
5 4
6 25
7 277
8 162
9 48
10 543
11 38409
12 18136
13 6912
14 1536
15 29281
16 23169481
17 7195590
18 2346000
19 691200
20 122880

List of values

[1, 1, 1, 3, 9, 4, 25, 277, 162, 48, 543, 38409, 18136, 6912, 1536, 29281, 23169481, 7195590, 2346000, 691200, 122880]

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

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