A207995 Number of nX6 0..2 arrays with new values 0..2 introduced in row major order and no element equal to any horizontal or vertical neighbor (colorings ignoring permutations of colors).

16, 243, 3891, 63267, 1034073, 16932816, 277458045, 4547477370, 74538711609, 1221819475953, 20027983390866, 328298744831580, 5381481886580865, 88213445048426316, 1445998260462433698, 23702862077090281716

Offset

1,1

Comments

Column 6 of A207997.

Links

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

Index entries for linear recurrences with constant coefficients, signature (30,-291,1278,-2901,3519,-2152,516).

Formula

a(n) = 30*a(n-1) -291*a(n-2) +1278*a(n-3) -2901*a(n-4) +3519*a(n-5) -2152*a(n-6) +516*a(n-7).

G.f.: -x*(16-237*x+1257*x^2-3198*x^3+4206*x^4-2736*x^5+688*x^6) / ( -1+30*x-291*x^2+1278*x^3-2901*x^4+3519*x^5-2152*x^6+516*x^7 ). - R. J. Mathar, Nov 23 2015

Example

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

Crossrefs

Sequence in context: A074153 A119933 A274753 * A008788 A360759 A219671

Adjacent sequences: A207992 A207993 A207994 * A207996 A207997 A207998

Keyword

nonn

Author

R. H. Hardin, Feb 22 2012

Status

approved