A185831 Half the number of nX5 binary arrays with every element equal to exactly one or two of its horizontal and vertical neighbors

3, 61, 393, 2398, 15782, 98975, 649826, 4143707, 26679121, 171597547, 1102725806, 7092378045, 45590856963, 293158517847, 1884832244162, 12118696565347, 77918494954731, 500981651046567, 3221109348385647, 20710370917938021

Offset

1,1

Comments

Column 5 of A185835

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Example

Some solutions for 4X5 with a(1,1)=0
..0..0..1..0..0....0..1..1..0..1....0..0..1..1..1....0..1..1..0..0
..1..0..1..0..0....0..0..1..0..1....0..1..1..0..1....0..0..1..0..1
..1..0..1..1..1....1..1..0..0..1....1..0..0..0..1....1..0..0..0..1
..1..0..0..0..1....0..0..0..1..1....1..1..1..1..1....1..1..1..1..1

Crossrefs

Sequence in context: A181505 A105430 A141979 * A301666 A102720 A120308

Adjacent sequences: A185828 A185829 A185830 * A185832 A185833 A185834

Keyword

nonn

Author

R. H. Hardin Feb 05 2011

Status

approved