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A266501 Number of n X n (0,1)-matrices such that there is a row and a column with equal sums. 1
1, 2, 12, 500, 63828, 33394572, 68548156212, 562584834624864 (list; graph; refs; listen; history; text; internal format)
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 A050643

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

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Last modified September 23 20:31 EDT 2021. Contains 347617 sequences. (Running on oeis4.)