A215872 Number of permutations of 0..floor((4*n-2)/2) on odd squares of an 4Xn array such that each row, column, diagonal and (downwards) antidiagonal of odd squares is increasing.

1, 1, 1, 4, 10, 78, 262, 3001, 11694, 170594, 727846, 12517074, 56797272, 1100044792, 5219906670, 110598847073, 542976951374, 12341741030502

Offset: 1

Author

R. H. Hardin Aug 25 2012

Keywords

• nonn

Comments

Row 4 of A215870

Examples

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