A185821 1/5 the number of n X 5 0..4 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

9, 5680, 1266624, 378212944, 100480040192, 28043363244452, 7662203273902712, 2112817100467905536, 580282378007177354752, 159650092398206756238532, 43890600560593534666234904, 12070254095603726713513018032

Offset: 1

Author

R. H. Hardin, Feb 05 2011

Keywords

• nonn

Comments

Column 5 of A185825.

Examples

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

Crossrefs

Cf. A185825.