A186166 1/4 the number of n X 7 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

40, 99933, 87054174, 95752776009, 96951738076992, 101554003879403823

Offset

1,1

Comments

Column 7 of A186168.

Links

Table of n, a(n) for n=1..6.

Example

Some solutions for 4 X 7 with a(1,1) = 0
..0..0..2..0..0..0..1....0..0..2..0..0..3..0....0..0..2..0..0..0..0
..0..0..2..0..2..2..1....0..0..2..0..3..3..0....0..0..2..0..2..2..1
..2..2..0..2..3..3..1....2..2..0..2..3..0..1....2..2..0..1..2..1..1
..0..0..0..2..3..2..2....0..0..0..2..0..0..1....0..0..0..1..1..3..3

Crossrefs

Cf. A186168.

Sequence in context: A323489 A266157 A223103 * A151605 A253107 A300842

Adjacent sequences: A186163 A186164 A186165 * A186167 A186168 A186169

Keyword

nonn

Author

R. H. Hardin Feb 13 2011

Status

approved