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

1,1

Comments

Column 4 of A185903

Links

Table of n, a(n) for n=1..12.

Example

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

Crossrefs

Sequence in context: A233122 A017547 A046248 * A078525 A280282 A125539

Adjacent sequences: A185898 A185899 A185900 * A185902 A185903 A185904

Keyword

nonn

Author

R. H. Hardin, Feb 06 2011

Status

approved