A252923 Number of n X n nonnegative integer arrays with upper left 0 and lower right n+n-6 and value increasing by 0 or 1 with every step right or down.

0, 0, 1, 615, 84910, 8241540, 759337545, 73117894428, 7578889491370, 848729993032718, 102072779621746876, 13069744040275286234, 1766655687081261435255, 250232365919081938956865, 36910187948533534644694094

Offset: 1

Author

R. H. Hardin, Dec 24 2014

Keywords

• nonn

Examples

			Some solutions for n=4
..0..0..1..1....0..0..1..1....0..1..1..1....0..0..1..2....0..0..0..1
..0..0..1..2....0..0..1..2....0..1..2..2....0..1..1..2....0..0..1..2
..0..1..2..2....1..1..1..2....0..1..2..2....1..1..1..2....0..1..2..2
..1..1..2..2....1..2..2..2....1..1..2..2....1..1..1..2....1..2..2..2
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..20 (first 15 terms from R. H. Hardin)

Crossrefs

Diagonal of A252930.