A185901 1/8 the number of nX4 0..7 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

8, 2765, 546280, 139230658, 32611077940, 7921723799549, 1897334511466261, 457135757368429048, 109875454057222039886, 26435697398605508731039, 6357732815393016703934708, 1529282331683348275213637905

Offset: 1

Author

R. H. Hardin Feb 06 2011

Keywords

• nonn

Comments

Column 4 of A185903

Examples

			Some solutions for 3X4 with a(1,1)=0
..0..4..4..3....0..0..6..6....0..4..1..0....0..0..4..5....0..0..5..4
..0..0..1..3....2..0..3..3....0..4..1..0....4..0..4..5....0..6..5..4
..6..6..1..1....2..2..2..3....7..7..2..2....4..0..3..3....0..6..3..3