A202553 Number of n X n 0,1 arrays with the row and column sums nondecreasing

2, 8, 66, 1526, 103806, 22360610, 15635171834, 36727396390100

Offset

1,1

Comments

Diagonal of A202560

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A086594 A132219 A226730 * A023164 A053922 A030445

Adjacent sequences: A202550 A202551 A202552 * A202554 A202555 A202556

Keyword

nonn

Author

R. H. Hardin Dec 21 2011

Status

approved