A233198 Number of n X 4 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, 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).

11, 528, 62720, 7802880, 981532672, 123833679872, 15635845218304, 1974688792182784, 249403601212932096, 31500304517060100096, 3978590250109478371328, 502509651344957204594688

Offset

1,1

Links

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

Formula

Empirical: a(n) = 208*a(n-1) - 13312*a(n-2) + 442368*a(n-3) - 8650752*a(n-4) + 67108864*a(n-5) for n>6.

Empirical g.f.: x*(11 - 1760*x + 99328*x^2 - 3080192*x^3 + 55050240*x^4 - 369098752*x^5) / ((1 - 16*x)*(1 - 192*x + 10240*x^2 - 278528*x^3 + 4194304*x^4)). - Colin Barker, Oct 10 2018

Example

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

Crossrefs

Column 4 of A233202.

Sequence in context: A004800 A322065 A065823 * A358162 A049654 A179897

Adjacent sequences: A233195 A233196 A233197 * A233199 A233200 A233201

Keyword

nonn

Author

R. H. Hardin, Dec 05 2013

Status

approved