A233170 Number of n X 4 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).

10, 800, 78336, 7938048, 808583168, 82428559360, 8403942375424, 856833627521024, 87359712110051328, 8906889846866313216, 908115313250288009216, 92588259810472408121344, 9439975016878714881310720

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 128*a(n-1) - 2816*a(n-2) + 16384*a(n-3).

Empirical g.f.: 2*x*(5 - 240*x + 2048*x^2) / ((1 - 16*x)*(1 - 112*x + 1024*x^2)). - Colin Barker, Oct 10 2018

Example

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

Crossrefs

Column 4 of A233174.

Sequence in context: A015057 A302133 A322918 * A211913 A347845 A006440

Adjacent sequences: A233167 A233168 A233169 * A233171 A233172 A233173

Keyword

nonn

Author

R. H. Hardin, Dec 05 2013

Status

approved