A186164 1/4 the number of nX5 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

7, 2175, 253341, 37402872, 5033988714, 704281652979, 96951738076992, 13435825601048421, 1856827788245959473, 256908205340960558187, 35528479510856892673200, 4914300705034627821533085

Offset: 1

Author

R. H. Hardin Feb 13 2011

Keywords

• nonn

Comments

Column 5 of A186168

Examples

			Some solutions for 4X5 with a(1,1)=0
..0..0..0..1..1....0..0..0..0..0....0..0..0..3..3....0..0..0..2..2
..0..2..0..1..2....0..2..1..1..1....0..2..0..1..3....0..2..0..2..1
..1..2..2..1..2....0..2..2..3..3....0..2..2..1..1....0..2..0..3..1
..1..1..0..0..2....3..3..3..0..0....0..3..3..0..0....0..2..0..3..3
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..21