A233169 Number of n X n 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs)

1, 8, 2688, 7938048, 221463445504, 48667983827959808, 95229762257179140685824, 1517114635517382193142028042240, 212050285595421539693130354498977398784, 244891984772140151804896156943078190424499683328

Offset

1,2

Comments

Diagonal of A233174

Links

R. H. Hardin, Table of n, a(n) for n = 1..13

Example

Some solutions for n=3
..0..1..2....0..1..2....0..1..2....0..1..5....0..1..5....0..1..2....0..1..0
..2..4..2....5..1..5....2..1..3....5..4..0....0..4..2....0..4..5....0..2..0
..3..4..5....2..4..0....2..4..2....2..4..2....5..4..2....3..1..2....5..3..4

Crossrefs

Sequence in context: A210126 A259440 A172957 * A233122 A017547 A046248

Adjacent sequences: A233166 A233167 A233168 * A233170 A233171 A233172

Keyword

nonn

Author

R. H. Hardin, Dec 05 2013

Status

approved