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.

A088672 Number of n X n (0,1)-matrices with zero permanent.

Original entry on oeis.org

0, 1, 9, 265, 27713, 10363361, 13906734081, 68121583929729
Offset: 0

Views

Author

Michael Somos, Oct 03 2003

Keywords

Crossrefs

Programs

  • Mathematica
    a[ n_] := Count[Table[Permanent[Partition[a, n]], {a, Tuples[{0, 1}, n^2]}], 0]; (* Michael Somos, Aug 05 2018 *)

Formula

a(n) is asymptotic to n*(2^(n^2 - n + 1)). [Everett and Stein]
a(n) = A002416(n) - A227414(n). - Geoffrey Critzer, Dec 19 2023

Extensions

a(5) from Jaap Spies, Nov 02 2003
a(6) from Gordon F. Royle, Nov 03 2003
a(7) added by Geoffrey Critzer, Dec 19 2023 after Noam Zeilberger in A227414.
a(0)=0 prepended by Alois P. Heinz, Dec 19 2023