A199648 Number of n X n 0..2 arrays with values 0..2 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors

1, 14, 2584, 3695683, 39209840355, 3083761998081891, 1797997097480559332224, 7771716024559573445914487875

Offset

1,2

Comments

Diagonal of A199655

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=3
..0..1..0....0..0..1....0..1..2....0..0..1....0..1..0....0..1..1....0..0..0
..0..0..1....1..0..2....0..1..2....2..2..2....2..0..0....1..2..2....0..1..1
..2..0..1....2..1..0....1..1..0....1..1..2....2..0..1....1..2..1....0..1..0

Crossrefs

Sequence in context: A080690 A268424 A079918 * A271401 A013719 A145188

Adjacent sequences: A199645 A199646 A199647 * A199649 A199650 A199651

Keyword

nonn

Author

R. H. Hardin Nov 08 2011

Status

approved