A266474 Number of 7Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nonincreasing.

8, 42, 303, 2574, 22128, 175180, 1231170, 7652503, 42460424, 212971589, 977395362, 4147719749, 16420984346, 61103700814, 215040758842, 719522481940, 2299243641848, 7043942786447, 20758083457211, 59015575393057

Offset

1,1

Comments

Row 7 of A266470.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

R. H. Hardin, Empirical polynomial of degree 34

Formula

Empirical polynomial of degree 34 (see link above)

Example

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

Crossrefs

Cf. A266470.

Sequence in context: A047772 A204565 A020068 * A238723 A316283 A236328

Adjacent sequences: A266471 A266472 A266473 * A266475 A266476 A266477

Keyword

nonn

Author

R. H. Hardin, Dec 29 2015

Status

approved