A266501 Number of n X n (0,1)-matrices such that there is a row and a column with equal sums.

1, 2, 12, 500, 63828, 33394572, 68548156212, 562584834624864

Offset

0,2

Comments

The ratio a(n)/2^(n^2) tends to 1 as n grows.

Links

Table of n, a(n) for n=0..7.

Mathoverflow, A partition of the set of all n x n (0,1)-matrices, 2015.

Formula

a(n) = 2^(n^2) - A266500(n).

Crossrefs

Sequence in context: A013173 A013147 A250110 * A264952 A324790 A371202

Adjacent sequences: A266498 A266499 A266500 * A266502 A266503 A266504

Keyword

nonn,hard,more

Author

Max Alekseyev, Dec 30 2015

Extensions

a(6)-a(7) from Hiroaki Yamanouchi, Dec 31 2015

Status

approved