A199141 Number of n X n 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors

0, 3, 132, 125468, 839006010, 44832664800117

Offset

1,2

Comments

Diagonal of A199149

Links

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

Example

Some solutions for n=4
..0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..1....0..0..1..1
..1..1..0..0....2..2..3..3....1..1..1..0....0..0..2..2....2..3..3..0
..2..2..0..3....2..2..0..0....2..0..0..0....2..2..3..2....2..0..0..0
..0..0..3..3....0..0..2..2....2..2..2..2....1..1..3..2....3..3..3..3

Crossrefs

Sequence in context: A262643 A048796 A213203 * A152435 A239426 A157086

Adjacent sequences: A199138 A199139 A199140 * A199142 A199143 A199144

Keyword

nonn

Author

R. H. Hardin Nov 03 2011

Status

approved