A215792 Number of permutations of 0..floor((6*n-1)/2) on even squares of an 6*n array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing.

1, 1, 1, 4, 50, 458, 15485, 234217, 14296434, 297246092, 26970790176

Offset: 1

Author

R. H. Hardin Aug 23 2012

Keywords

• nonn

Comments

Row 6 of A215788

Examples

			Some solutions for n=5
..0..x..1..x..4....0..x..1..x..2....0..x..1..x..4....0..x..1..x..2
..x..2..x..5..x....x..3..x..4..x....x..2..x..5..x....x..3..x..4..x
..3..x..6..x..8....5..x..6..x..7....3..x..6..x..8....5..x..6..x..8
..x..7..x.10..x....x..8..x..9..x....x..7..x..9..x....x..7..x..9..x
..9..x.11..x.13...10..x.11..x.13...10..x.11..x.13...10..x.11..x.12
..x.12..x.14..x....x.12..x.14..x....x.12..x.14..x....x.13..x.14..x