A186166 1/4 the number of n X 7 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

40, 99933, 87054174, 95752776009, 96951738076992, 101554003879403823

Offset: 1

Author

R. H. Hardin Feb 13 2011

Keywords

• nonn

Comments

Column 7 of A186168.

Examples

			Some solutions for 4 X 7 with a(1,1) = 0
..0..0..2..0..0..0..1....0..0..2..0..0..3..0....0..0..2..0..0..0..0
..0..0..2..0..2..2..1....0..0..2..0..3..3..0....0..0..2..0..2..2..1
..2..2..0..2..3..3..1....2..2..0..2..3..0..1....2..2..0..1..2..1..1
..0..0..0..2..3..2..2....0..0..0..2..0..0..1....0..0..0..1..1..3..3
		

Crossrefs

Cf. A186168.