A266466 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 4 of A266470.

LINKS

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

EXAMPLE

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

CROSSREFS

Cf. A266470.

Sequence in context: A275755 A150085 A306175 * A005654 A150086 A150087

Adjacent sequences: A266463 A266464 A266465 * A266467 A266468 A266469

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 29 2015

STATUS

approved