A250722 Number of (n+1) X (n+1) 0..1 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

9, 46, 208, 885, 3605, 14437, 57397, 228455, 912438, 3661515, 14755226, 59674645, 241996099, 983339540, 4001469252, 16299591564, 66441841973, 270971703338, 1105502740041, 4511347592849, 18413367334909, 75165710188419

Offset

1,1

Comments

Diagonal of A250729.

Links

R. H. Hardin, Table of n, a(n) for n = 1..30

Example

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

Crossrefs

Cf. A250729.

Sequence in context: A085385 A217152 A081193 * A250776 A054140 A307955

Adjacent sequences: A250719 A250720 A250721 * A250723 A250724 A250725

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved