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%I #8 Feb 04 2019 10:23:32
%S 12,56,232,988,4180,17712,75024,317812,1346268,5702888,24157816,
%T 102334156,433494436,1836311904,7778742048,32951280100,139583862444,
%U 591286729880,2504730781960,10610209857724,44945570212852
%N Number of 5 X n 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.
%H R. H. Hardin, <a href="/A275505/b275505.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) + 5*a(n-2) + a(n-3).
%F Conjectures from _Colin Barker_, Feb 04 2019: (Start)
%F G.f.: 4*x*(3 + 5*x + x^2) / ((1 + x)*(1 - 4*x - x^2)).
%F a(n) = (10*(-1)^n + (15-7*sqrt(5))*(2-sqrt(5))^n + (2+sqrt(5))^n*(15+7*sqrt(5))) / 10.
%F (End)
%e Some solutions for n=4:
%e ..0..1..1..2. .0..1..2..0. .0..0..1..1. .0..1..1..2. .0..0..0..0
%e ..0..1..2..0. .1..2..2..0. .0..1..2..2. .1..1..2..0. .1..1..1..1
%e ..1..2..0..0. .1..2..0..1. .1..2..2..0. .2..2..0..0. .1..2..2..2
%e ..1..2..0..1. .2..0..0..1. .2..2..0..1. .2..0..0..1. .2..2..0..0
%e ..2..0..1..1. .0..0..1..2. .2..0..0..1. .1..1..1..2. .0..0..1..1
%Y Row 5 of A275504.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jul 30 2016
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