A050204 a(n) is the number of n X n matrices of 0's, 1's and -1's in which the entries in each row or column sum to 1.

1, 2, 21, 1344, 628080, 2030271480, 49846153939785, 9350902053107858880, 13807842729396124460629536, 162526525004284727135887319788800, 15464071313054035722739424623204673044920, 12011244510939290610945342901003078567310643860160

Offset: 1

Author

Eric W. Weisstein

Keywords

• nonn

Crossrefs

Cf. A005130 (Robbins numbers).

Cf. A229165 (entries in each row or column sum to 1 and there are no adjacent -1's or 1's in any row or column).

Cf. A172645 (case row and column sums are zero).

Extensions

Definition corrected by Murphy Waggoner and R. H. Hardin, Sep 24 2013

a(6)-a(8) from R. H. Hardin, Sep 25 2013

a(9)-a(12) from Andrew Howroyd, Feb 03 2021