A185407 1/7 the number of nX4 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

7, 1848, 279918, 53808534, 9560464068, 1755419411964, 318289797234978, 58009184105051760, 10550717546713596858, 1920558372882730002666, 349484670721711744198032, 63604421284059206327321532

Offset: 1

Author

R. H. Hardin Jan 26 2011

Keywords

• nonn

Comments

Column 4 of A185409

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..20