A267239 Number of n X n binary arrays with row sums nondecreasing and columns lexicographically nondecreasing.

2, 7, 42, 567, 20040, 2093467, 683027146, 723576702570, 2549735632656528, 30465608408449993885, 1250919952257037350168062, 178764247753852768666003981113, 89752660973687899647122735126286078

Offset

1,1

Comments

Diagonal of A267245.

Links

Table of n, a(n) for n=1..13.

Example

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

Crossrefs

Cf. A267245.

Sequence in context: A091669 A108042 A152559 * A001174 A067975 A065298

Adjacent sequences: A267236 A267237 A267238 * A267240 A267241 A267242

Keyword

nonn

Author

R. H. Hardin, Jan 12 2016

Status

approved