A221250 Number of n X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

0, 4, 30, 58081, 78633756, 4919350997521, 720107530988047980, 2283974100099963226425600

Offset: 1

Author

R. H. Hardin Jan 06 2013

Keywords

• nonn

Comments

Diagonal of A221255

Examples

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