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%I #9 Mar 29 2018 08:49:03
%S 3,9,36,128,540,2048,8256,32784,131328,524288,2098368,8388608,
%T 33558528,134217984,536887296,2147483648,8590003200,34359738368,
%U 137439215616,549755817984,2199024304128,8796093022208,35184376332288,140737488355328
%N Half the number of n X 2 0..2 arrays with no element equal to the sum mod 3 of its horizontal and vertical neighbors.
%C Column 2 of A183501.
%H R. H. Hardin, <a href="/A183495/b183495.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 4*a(n-1) + 4*a(n-2) - 16*a(n-3) + 16*a(n-6) - 64*a(n-7) - 64*a(n-8) + 256*a(n-9)
%F Empirical g.f.: x*(3 - 3*x - 12*x^2 - 4*x^3 + 28*x^4 - 48*x^5 - 96*x^6 + 256*x^7 + 128*x^8) / ((1 - 2*x)*(1 + 2*x)*(1 - 4*x)*(1 - 4*x^3)*(1 + 4*x^3)). - _Colin Barker_, Mar 29 2018
%e Some solutions for 3 X 2:
%e ..0..2....1..0....2..0....1..1....2..1....1..1....2..0....0..0....0..0....1..2
%e ..2..1....2..1....0..0....1..1....0..0....1..2....0..0....1..2....1..1....0..0
%e ..0..2....2..1....0..2....1..1....2..0....2..2....2..1....1..2....2..2....1..2
%Y Cf. A183501.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 05 2011
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