A266424 Number of nX4 binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

5, 25, 106, 404, 1391, 4383, 12758, 34611, 88206, 212609, 487630, 1069664, 2254259, 4581719, 9011222, 17200214, 31944220, 57853902, 102380657, 177341666, 301156443, 502075951, 822789263, 1326908069, 2107999291, 3302022425

Offset

1,1

Comments

Column 4 of A266428.

Links

R. H. Hardin, Table of n, a(n) for n = 1..66

Example

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

Crossrefs

Cf. A266428.

Sequence in context: A218264 A264018 A067971 * A224129 A111641 A074419

Adjacent sequences: A266421 A266422 A266423 * A266425 A266426 A266427

Keyword

nonn

Author

R. H. Hardin, Dec 29 2015

Status

approved