A201370 Number of n X n 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.

2, 3, 8, 36, 268, 3739, 115168, 8866257, 1799674094, 976134459840

Offset: 1

Author

R. H. Hardin Nov 30 2011

Keywords

• nonn

Comments

Diagonal of A201375

Examples

			Some solutions for n=5
..0..1..1..1..1....0..0..0..0..1....0..1..1..1..1....0..0..1..1..1
..1..0..1..1..1....0..0..0..1..0....1..0..0..1..1....0..1..0..0..1
..1..1..0..0..1....0..1..1..0..0....1..0..0..1..1....0..1..1..1..0
..1..1..0..1..0....1..0..1..0..0....1..1..1..0..0....1..0..1..1..0
..1..1..1..0..0....1..1..0..0..0....1..1..1..0..0....1..1..0..0..0