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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.

A370385 Triangular array read by rows. T(n,k) is the number of binary relations R on [n] such that the unique idempotent relation in {R^i:i>=1} is a quasi-order containing exactly k strongly connected components.

Table of values

n a(n)
1 1
2 1
3 3
4 4
5 139
6 66
7 48
8 25575
9 9280
10 3072
11 1536
12 18077431
13 4498530
14 1174800
15 322560
16 122880

List of values

[1, 1, 3, 4, 139, 66, 48, 25575, 9280, 3072, 1536, 18077431, 4498530, 1174800, 322560, 122880]

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

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