A186165 1/4 the number of nX6 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

19, 14748, 4762206, 1899336597, 704281652979, 268995986029278, 101554003879403823, 38514280297010210802

Offset: 1

Author

R. H. Hardin Feb 13 2011

Keywords

• nonn

Comments

Column 6 of A186168

Examples

			Some solutions for 4X6 with a(1,1)=0
..0..0..0..2..2..2....0..0..0..2..2..0....0..0..0..2..2..0....0..0..0..2..2..0
..0..2..0..0..0..2....0..2..0..0..2..0....0..2..0..0..0..0....0..2..0..0..3..0
..3..2..1..2..0..3....3..2..1..1..2..0....0..2..2..2..2..2....1..2..2..3..3..0
..3..1..1..2..0..3....3..0..0..0..2..0....0..0..0..0..1..1....1..0..0..3..2..2