A217339 Number of n X n arrays of occupancy after each element moves to some horizontal or vertical neighbor but without 2-loops.

0, 1, 144, 120908, 838126848, 52019083898820

Offset

1,3

Links

Table of n, a(n) for n=1..6.

Example

Some solutions for n=3
..1..2..0....1..0..0....1..1..0....0..2..0....1..2..0....1..2..1....1..1..1
..1..3..0....2..1..1....1..1..2....1..3..1....2..2..0....1..1..2....2..1..2
..0..2..0....1..2..1....1..1..1....0..1..1....0..1..1....1..0..0....1..0..0

Crossrefs

Diagonal of A217346.

Sequence in context: A187464 A221735 A272462 * A231827 A203098 A159724

Adjacent sequences: A217336 A217337 A217338 * A217340 A217341 A217342

Keyword

nonn

Author

R. H. Hardin, Oct 01 2012

Status

approved