A189428 Number of n X n array permutations with each element not moving, or moving one space N, SW or SE.

1, 2, 9, 140, 5680, 606201, 181540773, 150293731826, 343426652577376

Offset: 1

Author

R. H. Hardin Apr 22 2011

Keywords

• nonn

Comments

Diagonal of A189435

Examples

			Some solutions for 3X3
..0..4..2....0..1..2....0..1..2....0..1..2....0..1..5....0..4..5....3..1..2
..3..7..1....3..4..5....6..7..5....3..7..8....3..2..8....3..2..1....6..0..5
..6..5..8....6..7..8....4..3..8....6..5..4....6..7..4....6..7..8....4..7..8