A193481 Number of n X n symmetric 0..2 arrays with each element equal to the product mod 3 of two of its horizontal and vertical neighbors

0, 2, 8, 127, 3686, 285929, 47398400, 18127384939, 15993244772677, 32531416116323498, 152344987111028997103, 1640044640940871976733780

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Example

Some solutions for 4X4
..1..2..1..2....1..2..2..1....1..2..0..0....1..1..1..1....1..2..1..1
..2..2..1..2....2..2..1..2....2..2..1..0....1..1..1..1....2..2..1..1
..1..1..1..2....2..1..1..2....0..1..2..2....1..1..1..0....1..1..1..1
..2..2..2..1....1..2..2..1....0..0..2..1....1..1..0..0....1..1..1..1

Crossrefs

Sequence in context: A271846 A009360 A202648 * A156497 A064205 A081856

Adjacent sequences: A193478 A193479 A193480 * A193482 A193483 A193484

Keyword

nonn

Author

R. H. Hardin Jul 27 2011

Status

approved