A266466 Number of nX4 binary arrays with rows and columns lexicographically nondecreasing and column sums nonincreasing.

2, 6, 19, 66, 232, 794, 2574, 7797, 22058, 58469, 146027, 345578, 779240, 1682359, 3492869, 6999952, 13585959, 25610002, 47004982, 84187248, 147421139, 252829908, 425319569, 702767285, 1141951244, 1826839569, 2880058656, 4478585700

Offset: 1

Author

R. H. Hardin, Dec 29 2015

Keywords

• nonn

Comments

Column 4 of A266470.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..67

Crossrefs

Cf. A266470.