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

1,2

Comments

Diagonal of A189435

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Sequence in context: A064448 A173215 A110817 * A110860 A370556 A050995

Adjacent sequences: A189425 A189426 A189427 * A189429 A189430 A189431

Keyword

nonn

Author

R. H. Hardin Apr 22 2011

Status

approved