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

1,1

Comments

Diagonal of A266470.

Links

Table of n, a(n) for n=1..11.

Example

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.

Sequence in context: A137160 A217716 A129824 * A013207 A172165 A078919

Adjacent sequences: A266460 A266461 A266462 * A266464 A266465 A266466

Keyword

nonn

Author

R. H. Hardin, Dec 29 2015

Status

approved