A250520 Number of (n+1)X(n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction.

50, 1180, 21955, 300131, 3183434, 27910024, 212707851, 1462376991, 9314700106, 56025183452, 322542598187

Offset: 1

Author

R. H. Hardin, Nov 24 2014

Keywords

• nonn

Comments

Diagonal of A250527

Examples

			Some solutions for n=3
..2..1..2..1....1..1..0..0....2..2..1..1....2..1..2..0....2..0..1..0
..1..0..1..0....0..0..0..0....1..1..0..0....2..1..2..1....2..1..2..2
..1..1..2..1....1..1..2..2....2..2..1..1....1..1..2..2....2..1..2..2
..0..0..2..1....0..1..2..2....0..2..1..2....0..1..2..2....0..1..2..2