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
Keywords
Examples
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
Links
- R. H. Hardin, Table of n, a(n) for n = 1..66
Crossrefs
Cf. A266428.
Comments