A183408 Number of n X n binary arrays with each sum of a(1..i,1..j) no greater than i*j/2 and rows and columns in nondecreasing order

1, 5, 22, 380, 11499, 1497764, 408834576, 475512062908

Offset

1,2

Comments

Diagonal of A183413

Links

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

Example

Some solutions for 4X4
..0..0..1..1....0..0..0..1....0..0..0..1....0..0..0..0....0..0..0..0
..0..1..0..0....0..0..0..1....0..0..1..0....0..0..0..0....0..0..1..1
..0..1..0..0....0..0..0..1....0..1..1..0....0..1..1..1....0..0..1..1
..1..1..0..0....0..0..1..1....1..0..1..0....1..0..0..0....0..1..1..1

Crossrefs

Sequence in context: A066865 A183902 A005632 * A298322 A299215 A300031

Adjacent sequences: A183405 A183406 A183407 * A183409 A183410 A183411

Keyword

nonn

Author

R. H. Hardin Jan 04 2011

Status

approved