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%I #7 Feb 04 2019 14:12:06
%S 3,54,126,294,672,1536,3552,8214,19092,44376,103200,240000,558000,
%T 1297350,3015990,7011366,16299318,37891014,88085676,204773784,
%U 476041212,1106661366,2572675992,5980747104,13903551072,32321836896,75139155000
%N Number of 3 X n 0..2 arrays with no element equal to any value at offset (-2,0) (-1,2) or (0,-2) and new values introduced in order 0..2.
%H R. H. Hardin, <a href="/A275566/b275566.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) - 5*a(n-3) + a(n-4) + 7*a(n-5) - 5*a(n-6) + 2*a(n-8) - a(n-9) for n>10.
%F Empirical g.f.: 3*x*(1 + 15*x - 12*x^2 - 23*x^3 + 19*x^4 + 25*x^5 - 25*x^6 + 4*x^7 + 8*x^8 - 5*x^9) / ((1 - 3*x + 2*x^2 - x^3)*(1 - 2*x^2 + 3*x^4 - x^6)). - _Colin Barker_, Feb 04 2019
%e Some solutions for n=4:
%e ..0..0..1..1. .0..1..2..0. .0..1..2..0. .0..0..1..1. .0..1..2..0
%e ..2..0..0..2. .1..2..2..0. .0..2..2..1. .0..2..2..0. .1..2..0..1
%e ..1..1..2..2. .1..2..0..1. .1..2..0..1. .1..1..0..2. .2..0..1..1
%Y Row 3 of A275565.
%K nonn
%O 1,1
%A _R. H. Hardin_, Aug 01 2016
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