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A183597 1/6 the number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock containing all three values.

%I A183597 #9 Mar 30 2018 09:09:25
%S A183597 120,1479,17174,201770,2366412,27768032,325834456,3823553752,
%T A183597 44868561272,526526214848,6178727749808,72506794636336,
%U A183597 850861000923008,9984783537547136,117170625132737568,1374987868096008576
%N A183597 1/6 the number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock containing all three values.
%C A183597 Column 3 of A183603.
%H A183597 R. H. Hardin, <a href="/A183597/b183597.txt">Table of n, a(n) for n = 1..200</a>
%F A183597 Empirical: a(n) = 12*a(n-1) + 20*a(n-2) - 238*a(n-3) - 420*a(n-4) + 324*a(n-5) + 400*a(n-6) - 224*a(n-7).
%F A183597 Empirical g.f.: x*(120 + 39*x - 2974*x^2 - 5338*x^3 + 4094*x^4 + 5400*x^5 - 3024*x^6) / (1 - 12*x - 20*x^2 + 238*x^3 + 420*x^4 - 324*x^5 - 400*x^6 + 224*x^7). - _Colin Barker_, Mar 30 2018
%e A183597 Some solutions with a(1,1)=0 for 3 X 4:
%e A183597 ..0..2..2..1....0..0..0..0....0..1..2..0....0..0..0..1....0..1..2..1
%e A183597 ..2..1..0..2....2..1..2..1....2..0..1..0....2..1..2..2....2..2..0..0
%e A183597 ..0..0..2..1....2..0..2..0....0..1..2..1....0..1..0..1....1..0..1..2
%Y A183597 Cf. A183603.
%K A183597 nonn
%O A183597 1,1
%A A183597 _R. H. Hardin_, Jan 05 2011