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

1,4

Comments

Row 4 of A215870

Links

Table of n, a(n) for n=1..18.

Example

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

Crossrefs

Sequence in context: A152397 A239502 A171754 * A059919 A143047 A156329

Adjacent sequences: A215869 A215870 A215871 * A215873 A215874 A215875

Keyword

nonn

Author

R. H. Hardin Aug 25 2012

Status

approved