A266422 Number of n X n binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

2, 7, 39, 404, 8764, 448649, 59155748, 21325003746, 21901867532457, 66087854484252677, 600640567173169508177

Offset

1,1

Comments

Diagonal of A266428.

Links

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

Example

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

Crossrefs

Cf. A266428.

Sequence in context: A367448 A052443 A153744 * A189826 A069732 A346964

Adjacent sequences: A266419 A266420 A266421 * A266423 A266424 A266425

Keyword

nonn

Author

R. H. Hardin, Dec 29 2015

Status

approved