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.

A213430 The number of n X n upper triangular (0,1)-matrices M with all diagonal entries 1 such that M = f(M^2) and sum(row 1) >= sum(row 2) >= ... >= sum(row n-1) >= sum(row n) = 1 and f maps any nonzero entry to 1.

Table of values

n a(n)
1 1
2 2
3 6
4 26
5 159
6 1347
7 15593
8 244173
9 5131436

List of values

[1, 2, 6, 26, 159, 1347, 15593, 244173, 5131436]

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

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