A215791 Number of permutations of 0..floor((5*n-1)/2) on even squares of an 5*n array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing.

1, 1, 1, 4, 25, 189, 2465, 26451, 530429, 7027942, 187205626, 2850280812

Offset: 1

Author

R. H. Hardin, Aug 23 2012

Keywords

• nonn
• more

Examples

			Some solutions for n=5:
..0..x..1..x..4....0..x..1..x..4....0..x..1..x..3....0..x..1..x..3
..x..2..x..5..x....x..2..x..5..x....x..2..x..4..x....x..2..x..5..x
..3..x..6..x..8....3..x..6..x..8....5..x..6..x..8....4..x..6..x..8
..x..7..x..9..x....x..7..x.10..x....x..7..x..9..x....x..7..x..9..x
.10..x.11..x.12....9..x.11..x.12...10..x.11..x.12...10..x.11..x.12
		

Crossrefs

Row 5 of A215788.