A233258 Number of 3 X n 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).

11, 136, 4672, 166400, 6049792, 220626944, 8050180096, 293762760704, 10720053821440, 391200251052032, 14275841005453312, 520959990903603200, 19011091850007150592, 693760794065113186304, 25317011997007519154176

Offset: 1

Author

R. H. Hardin, Dec 06 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 3 of A233256.

Formula

Empirical: a(n) = 48*a(n-1) - 448*a(n-2) + 1024*a(n-3) for n>5.

Empirical g.f.: x*(11 - 392*x + 3072*x^2 - 8192*x^3 + 16384*x^4) / ((1 - 8*x)*(1 - 40*x + 128*x^2)). - Colin Barker, Oct 11 2018