A233122 Number of n X n 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or vertically, 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, 10674176, 406142844928, 145451790488305664, 491056502853059022422016, 15650767090419537715133256040448, 4713550152014576979763161453081103695872

Offset

1,2

Comments

Diagonal of A233129

Links

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

Example

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

Crossrefs

Sequence in context: A259440 A172957 A233169 * A017547 A046248 A185901

Adjacent sequences: A233119 A233120 A233121 * A233123 A233124 A233125

Keyword

nonn

Author

R. H. Hardin, Dec 04 2013

Status

approved