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A183596 1/6 the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock containing all three values.

%I A183596 #9 Mar 30 2018 09:11:12
%S A183596 27,204,1479,10797,78729,574185,4187499,30539367,222722937,1624313781,
%T A183596 11846086563,86393262903,630064268913,4595045605149,33511572001131,
%U A183596 244399197416799,1782398262186441,12998993444433333,94801388754240819
%N A183596 1/6 the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock containing all three values.
%C A183596 Column 2 of A183603.
%H A183596 R. H. Hardin, <a href="/A183596/b183596.txt">Table of n, a(n) for n = 1..200</a>
%F A183596 Empirical: a(n) = 8*a(n-1) - 3*a(n-2) - 16*a(n-3) + 2*a(n-4).
%F A183596 Empirical g.f.: 3*x*(9 - 4*x - 24*x^2 + 3*x^3) / (1 - 8*x + 3*x^2 + 16*x^3 - 2*x^4). - _Colin Barker_, Mar 30 2018
%e A183596 Some solutions with a(1,1)=0 for 5 X 3:
%e A183596 ..0..2..1....0..2..1....0..0..2....0..0..2....0..2..0....0..2..0....0..1..2
%e A183596 ..0..1..0....1..0..1....2..1..1....2..1..0....1..2..1....0..1..0....0..2..0
%e A183596 ..1..2..2....1..2..0....1..0..2....0..1..2....2..0..0....1..2..1....1..2..1
%e A183596 ..0..1..0....0..2..1....2..0..1....2..0..1....1..2..1....2..0..2....1..0..1
%e A183596 ..0..2..2....1..1..0....2..1..2....1..2..1....0..1..0....1..1..2....0..2..1
%Y A183596 Cf. A183603.
%K A183596 nonn
%O A183596 1,1
%A A183596 _R. H. Hardin_, Jan 05 2011