A221336 Number of nX4 arrays of occupancy after each element stays put or moves to some king-move neighbor, with every occupancy equal to zero or two.

4, 68, 790, 10704, 142792, 1937900, 26264018, 356533300, 4838763426, 65677043240, 891388869206

Offset: 1

Author

R. H. Hardin Jan 11 2013

Keywords

• nonn

Comments

Column 4 of A221337

Examples

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