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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.
1

%I #8 Feb 02 2019 20:30:46

%S 16,162,2282,32388,460034,6534900,92831330,1318716132,18733040162,

%T 266112481908,3780264894914,53700610406820,762844837516610,

%U 10836603937486452,153939541994209442,2186790504309773028

%N 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.

%H R. H. Hardin, <a href="/A275231/b275231.txt">Table of n, a(n) for n = 1..210</a>

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

%F 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

%e Some solutions for n=4:

%e ..0..0..1..2. .0..1..2..2. .0..1..0..1. .0..1..2..1. .0..1..2..1

%e ..2..1..2..1. .1..0..1..0. .2..0..1..0. .1..2..1..0. .2..2..1..2

%e ..1..2..1..2. .2..1..0..1. .0..2..0..2. .0..1..0..1. .0..1..2..0

%e ..2..1..0..1. .1..0..1..0. .1..0..2..0. .1..0..1..0. .1..0..1..2

%e ..1..2..1..0. .0..1..2..2. .0..1..1..1. .0..1..2..1. .0..1..2..1

%e ..2..1..2..1. .1..2..1..0. .1..0..2..0. .1..0..1..2. .2..2..1..0

%Y Row 6 of A275228.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jul 20 2016