A193271 Number of n X n symmetric 0..5 arrays with no element equal to any horizontal or vertical neighbor and with new values 0..5 introduced in lower triangular row major order

1, 2, 42, 10455, 17957112, 139031457162, 4542089826393987, 623345036311461259086, 359303834921251677870936120, 869870085407321787861592624745847

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n = 1..11

Example

Some solutions for 4X4
..0..1..2..3....0..1..0..2....0..1..3..2....0..1..3..2....0..1..2..1
..1..2..0..2....1..2..3..5....1..2..0..1....1..2..4..1....1..2..0..4
..2..0..2..0....0..3..4..1....3..0..4..2....3..4..3..0....2..0..3..2
..3..2..0..2....2..5..1..5....2..1..2..0....2..1..0..5....1..4..2..0

Crossrefs

Sequence in context: A293864 A208297 A278150 * A193272 A193273 A182192

Adjacent sequences: A193268 A193269 A193270 * A193272 A193273 A193274

Keyword

nonn

Author

R. H. Hardin Jul 20 2011

Status

approved