A266463 Number of n X n binary arrays with rows and columns lexicographically nondecreasing and column sums nonincreasing.

2, 4, 12, 66, 735, 18808, 1231170, 223521350, 119000455681, 193166954325425, 983670413713595700

Offset: 1

Author

R. H. Hardin, Dec 29 2015

Keywords

• nonn

Comments

Diagonal of A266470.

Examples

			Some solutions for n=4
..0..0..0..0....0..0..1..1....0..0..0..1....0..0..0..0....0..1..1..1
..0..0..1..1....1..1..0..1....0..1..1..0....0..0..0..1....1..0..0..1
..1..1..0..0....1..1..1..0....1..0..0..0....0..0..1..0....1..0..1..0
..1..1..1..1....1..1..1..0....1..1..1..1....1..1..0..0....1..1..0..0
		

Crossrefs

Cf. A266470.