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Number of n X n binary arrays with rows lexicographically nondecreasing and columns lexicographically nondecreasing and row sums nondecreasing and column sums nonincreasing.
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%I #6 Apr 20 2020 19:44:26

%S 2,4,9,35,210,2577,68890,4605960,821453747

%N Number of n X n binary arrays with rows lexicographically nondecreasing and columns lexicographically nondecreasing and row sums nondecreasing and column sums nonincreasing.

%C Diagonal of A266935.

%e Some solutions for n=4

%e ..0..0..0..1....0..0..0..1....0..0..1..1....0..0..0..1....0..0..1..1

%e ..0..0..1..0....1..1..1..0....1..1..0..0....0..0..1..1....0..0..1..1

%e ..1..1..0..1....1..1..1..0....1..1..1..1....1..1..0..0....1..1..0..0

%e ..1..1..1..0....1..1..1..1....1..1..1..1....1..1..1..0....1..1..0..0

%Y Cf. A266935.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 06 2016