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%I #8 Mar 31 2012 12:37:30
%S 34,280,2304,19008,156800,1293568,10671616,88038400,726296576,
%T 5991780352,49430814720,407792893952,3364197924864,27753861939200,
%U 228963000909824,1888892288237568,15582928518512640,128555589286494208
%N Number of (n+1)X3 0..2 arrays with every 2X2 subblock having two distinct values, and new values 0..2 introduced in row major order
%C Column 2 of A209897
%H R. H. Hardin, <a href="/A209891/b209891.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 8*a(n-1) +4*a(n-2) -16*a(n-3).
%F Empirical G.f.: 2*x*(17+4*x-36*x^2)/(1-8*x-4*x^2+16*x^3). [Colin Barker, Mar 15 2012]
%e Some solutions for n=4
%e ..0..0..0....0..0..0....0..0..0....0..1..2....0..0..0....0..1..1....0..1..0
%e ..0..1..0....0..1..0....0..1..0....0..1..2....0..1..1....0..0..0....0..0..1
%e ..0..0..0....1..0..0....0..0..1....0..1..1....0..0..1....0..1..0....1..0..0
%e ..2..2..2....0..0..2....1..1..0....1..0..0....0..1..0....0..1..1....0..1..0
%e ..0..2..0....1..0..2....1..0..1....0..0..2....1..0..0....0..0..1....0..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 14 2012
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