A193481 - OEIS

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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

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

(list; graph; refs; listen; history; text; internal format)

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