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A275222 Number of n X 2 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.

%I A275222 #8 Feb 01 2019 11:58:16
%S A275222 2,6,11,27,66,162,404,1007,2512,6271,15655,39084,97580,243626,608259,
%T A275222 1518638,3791579,9466427,23634810,59008986,147327628,367832623,
%U A275222 918367048,2292885359,5724642759,14292705300,35684571668,89093606034,222439846275
%N A275222 Number of n X 2 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 A275222 R. H. Hardin, <a href="/A275222/b275222.txt">Table of n, a(n) for n = 1..210</a>
%F A275222 Empirical: a(n) = 3*a(n-1) - a(n-2) - 2*a(n-4) + a(n-5) for n>6.
%F A275222 Empirical g.f.: x*(1 + x - x^2)*(2 - 2*x - x^2 - x^3) / ((1 - x)*(1 - 2*x - x^2 - x^3 + x^4)). - _Colin Barker_, Feb 01 2019
%e A275222 Some solutions for n=4:
%e A275222 ..0..1. .0..0. .0..1. .0..1. .0..1. .0..1. .0..0. .0..1. .0..1. .0..1
%e A275222 ..1..0. .1..2. .1..0. .1..0. .2..0. .1..0. .1..2. .1..2. .1..0. .2..0
%e A275222 ..2..2. .2..1. .0..2. .2..1. .0..2. .0..1. .2..1. .2..1. .0..2. .0..1
%e A275222 ..1..0. .1..2. .2..0. .1..2. .1..1. .1..2. .0..0. .1..2. .1..0. .2..0
%Y A275222 Column 2 of A275228.
%K A275222 nonn
%O A275222 1,1
%A A275222 _R. H. Hardin_, Jul 20 2016