A221272 Number of nX4 arrays of occupancy after each element moves to some king-move neighbor, with every occupancy equal to zero or two.

1, 52, 596, 7252, 94659, 1250015, 16474842, 217194702, 2863102280, 37731750319, 497133557199, 6548899949298, 86261110576994, 1136131886838454

Offset: 1

Author

R. H. Hardin Jan 08 2013

Keywords

• nonn

Comments

Column 4 of A221273

Examples

			Some solutions for n=4
..0..2..2..0....0..2..0..2....0..2..2..2....0..2..2..0....0..2..2..2
..2..0..0..2....0..0..2..0....0..0..0..0....2..0..2..0....0..0..0..0
..0..2..2..0....2..2..0..2....2..0..2..0....0..2..0..2....0..2..2..2
..0..2..2..0....2..0..0..2....2..2..2..0....0..2..2..0....0..0..2..2