A229416 Number of n X n 0..3 zero-diagonal arrays with corresponding row and column sums equal.

1, 4, 136, 59008, 345706336, 28256240134144, 33097994593655140864

Offset: 1

Author

R. H. Hardin Sep 22 2013

Keywords

• nonn

Comments

Column 3 of A229417

Examples

			Some solutions for n=4
..0..2..3..3....0..0..0..1....0..1..2..0....0..3..2..0....0..3..0..1
..3..0..3..0....0..0..0..1....0..0..3..3....2..0..2..3....1..0..2..2
..2..3..0..3....0..0..0..3....3..2..0..3....0..2..0..3....3..0..0..1
..3..1..2..0....1..1..3..0....0..3..3..0....3..2..1..0....0..2..2..0