A276294 Number of n X 3 0..2 arrays with no element equal to any value at offset (-2,-1) (-1,1) or (0,-1) and new values introduced in order 0..2.

2, 12, 45, 189, 805, 3437, 14693, 62829, 268677, 1148973, 4913509, 21012333, 89858053, 384272941, 1643321829, 7027574381, 30053031045, 128520116269, 549609131621, 2350372894061, 10051239005445, 42983564779053

Offset: 1

Author

R. H. Hardin, Aug 28 2016

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 3 of A276299.

Formula

Empirical: a(n) = 6*a(n-1) - 8*a(n-2) + 4*a(n-3) - 7*a(n-4) + 6*a(n-5) for n>7.

Empirical g.f.: x*(2 - 11*x^2 + 7*x^3 - 3*x^4 + 11*x^5 - 2*x^6) / ((1 - x)*(1 - 5*x + 3*x^2 - x^3 + 6*x^4)). - Colin Barker, Feb 05 2019