A199643 Number of nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

2, 60, 1265, 29229, 658770, 15066222, 342328663, 7797114144, 177447181083, 4039488090307, 91947444344704, 2092999963213610, 47642308975551650, 1084472533833020100, 24685590900071146822, 561912613968766782369

Offset: 1

Author

R. H. Hardin Nov 08 2011

Keywords

• nonn

Comments

Column 4 of A199647

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200