A223614 Number of n X n 0..1 arrays with rows and columns unimodal

2, 16, 240, 4466, 89630, 1856100, 39162020, 840122330, 18350758538, 409124396540, 9333564282142, 218396645933584, 5252293916506694

Offset

1,1

Comments

Diagonal of A223620

Links

Table of n, a(n) for n=1..13.

Example

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

Crossrefs

Sequence in context: A376389 A280394 A376392 * A152029 A152069 A188767

Adjacent sequences: A223611 A223612 A223613 * A223615 A223616 A223617

Keyword

nonn

Author

R. H. Hardin Mar 24 2013

Status

approved