A233161 Number of n X n 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, diagonally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs)

1, 1, 96, 28672, 31457280, 133143986176, 2216615441596416, 146421031085069565952, 38534510500216304943759360, 40485591044789076510300958621696

Offset

1,3

Comments

Diagonal of A233168

Links

R. H. Hardin, Table of n, a(n) for n = 1..16

Example

Some solutions for n=4
..0..1..0..2....0..1..2..1....0..1..2..1....0..1..7..1....0..1..2..6
..3..5..3..6....5..3..7..3....5..3..0..3....2..3..5..3....5..3..0..4
..0..6..0..2....0..6..5..6....0..6..2..1....1..7..6..7....7..6..5..1
..4..2..3..6....2..4..7..3....5..3..0..4....4..5..3..5....5..4..7..3

Crossrefs

Sequence in context: A203489 A208794 A276099 * A269090 A232522 A296061

Adjacent sequences: A233158 A233159 A233160 * A233162 A233163 A233164

Keyword

nonn

Author

R. H. Hardin, Dec 05 2013

Status

approved