A221851 Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.

13, 3437, 465305, 67228149, 9607602488, 1374453486067, 196583533871825, 28117377558933453

Offset: 1

Author

R. H. Hardin Jan 27 2013

Keywords

• nonn

Comments

Column 4 of A221852

Examples

			Some solutions for n=3
..0..2..1..0....0..2..0..0....0..1..1..0....0..3..0..2....0..4..0..2
..0..0..3..0....0..1..7..0....1..0..1..4....0..1..0..2....0..0..1..0
..1..3..2..0....1..0..1..0....0..3..0..1....0..1..1..2....0..3..1..1