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
Keywords
Examples
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
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
Comments