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%I #11 Jun 18 2022 23:38:32
%S 272,476,832,1736,3536,8336,18832,48128,115952,312416,782032,2180576,
%T 5582576,15917216,41303632,119516768,312747632,914077856,2405006032,
%U 7078411616,18692677616,55290785696,146389598032,434571648608
%N Number of (n+1) X (3+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).
%H R. H. Hardin, <a href="/A235293/b235293.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) + 17*a(n-2) - 57*a(n-3) - 86*a(n-4) + 372*a(n-5) + 76*a(n-6) - 972*a(n-7) + 360*a(n-8) + 864*a(n-9) - 576*a(n-10).
%F Empirical g.f.: 4*x*(68 - 85*x - 1305*x^2 + 1663*x^3 + 8677*x^4 - 11152*x^5 - 23382*x^6 + 29868*x^7 + 21600*x^8 - 27072*x^9) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)*(1 - 8*x^2)). - _Colin Barker_, Oct 18 2018
%e Some solutions for n=5:
%e 0 0 0 3 2 2 2 1 0 3 0 0 1 2 1 3 3 3 3 3
%e 3 0 3 3 0 3 0 2 0 0 0 3 3 1 3 2 3 0 3 0
%e 3 3 3 0 3 3 3 2 0 3 0 0 1 2 1 3 1 1 1 1
%e 0 3 0 0 0 3 0 2 3 3 3 0 3 1 3 2 0 3 0 3
%e 0 0 0 3 1 1 1 0 0 3 0 0 1 2 1 3 0 0 0 0
%e 0 3 0 0 0 3 0 2 3 3 3 0 2 0 2 1 3 0 3 0
%Y Column 3 of A235301.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 05 2014
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