A233253 Number of n X 5 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally 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).

36, 13952, 6049792, 2647261184, 1159192379392, 507618560835584, 222290692443996160, 97343107609552486400, 42627429627049642295296, 18666938062087506825838592, 8174421486934238668125110272

Offset

1,1

Links

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

Formula

Empirical: a(n) = 512*a(n-1) - 33792*a(n-2) + 589824*a(n-3).

Empirical g.f.: 4*x*(9 - 1120*x + 30720*x^2) / ((1 - 32*x)*(1 - 480*x + 18432*x^2)). - Colin Barker, Oct 11 2018

Example

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

Crossrefs

Column 5 of A233256.

Sequence in context: A233126 A201003 A271335 * A134374 A263388 A159423

Adjacent sequences: A233250 A233251 A233252 * A233254 A233255 A233256

Keyword

nonn

Author

R. H. Hardin, Dec 06 2013

Status

approved