A275231 Number of 6 X n 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,0) and new values introduced in order 0..2.

16, 162, 2282, 32388, 460034, 6534900, 92831330, 1318716132, 18733040162, 266112481908, 3780264894914, 53700610406820, 762844837516610, 10836603937486452, 153939541994209442, 2186790504309773028

Offset: 1

Author

R. H. Hardin, Jul 20 2016

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 6 of A275228.

Formula

Empirical: a(n) = 19*a(n-1) - 75*a(n-2) + 101*a(n-3) - 44*a(n-4) for n>5.

Empirical g.f.: 2*x*(8 - 71*x + 202*x^2 - 218*x^3 + 77*x^4) / ((1 - x)*(1 - 18*x + 57*x^2 - 44*x^3)). - Colin Barker, Feb 02 2019