A213956 Number of n X n 0..2 matrices with row and column i=1..n having sum <= i*2.

3, 42, 3186, 1299735, 2860343784, 34107691901433, 2211749000480369037, 782349734245964422491828

Offset: 1

Author

R. H. Hardin Jun 28 2012

Keywords

• nonn

Comments

Column 2 of A213962

Examples

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