A233125 Number of nX4 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or vertically, 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, 896, 96256, 10674176, 1189609472, 132682612736, 14800557965312, 1651015493353472, 184172904936636416, 20544737466392772608, 2291793599167553601536, 255652719756086620454912

Offset

1,1

Comments

Column 4 of A233129

Links

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

Formula

Empirical: a(n) = 160*a(n-1) -6144*a(n-2) +86016*a(n-3) -393216*a(n-4).

Empirical: G.f.: -2*x*(-5+352*x-7168*x^2+40960*x^3) / ( (16*x-1)*(24576*x^3-3840*x^2+144*x-1) ). - R. J. Mathar, Oct 31 2015

Example

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

Crossrefs

Sequence in context: A054328 A203590 A263056 * A297471 A024137 A015008

Adjacent sequences: A233122 A233123 A233124 * A233126 A233127 A233128

Keyword

nonn

Author

R. H. Hardin, Dec 04 2013

Status

approved