A193499 Number of n X n symmetric 0..2 arrays with no element equal to the product mod 3 of any two of its horizontal and vertical neighbors

3, 11, 62, 508, 6113, 111924, 3135173, 135866492, 9010404513, 922993092986, 145088171122406, 35156227235312406, 13079571591787830274, 7493880039061547385152, 6595187964080142141837198

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..19

Example

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

Crossrefs

Sequence in context: A356268 A069725 A291287 * A261919 A232617 A326092

Adjacent sequences: A193496 A193497 A193498 * A193500 A193501 A193502

Keyword

nonn

Author

R. H. Hardin Jul 29 2011

Status

approved