%I #11 Jun 18 2022 23:38:23
%S 40,108,272,744,1888,5232,13376,37536,96640,274368,710912,2039424,
%T 5314048,15382272,40272896,117459456,308746240,906083328,2389348352,
%U 7047112704,18631057408,55167578112,146146082816,434084683776
%N Number of (n+1) X (1+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="/A235291/b235291.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 14*a(n-2) - 48*a(n-4).
%F Empirical g.f.: 4*x*(10 + 27*x - 72*x^2 - 192*x^3) / ((1 - 6*x^2)*(1 - 8*x^2)). - _Colin Barker_, Oct 18 2018
%e Some solutions for n=5:
%e 3 0 2 2 3 0 1 3 1 1 3 0 0 1 3 3 1 0 1 3
%e 1 1 3 0 1 1 2 1 0 3 2 2 3 1 0 3 0 2 3 2
%e 3 0 1 1 3 0 0 2 1 1 3 0 0 1 1 1 1 0 0 2
%e 0 0 3 0 2 2 2 1 0 3 2 2 3 1 3 0 0 2 1 0
%e 0 3 1 1 3 0 1 3 3 3 3 0 0 1 3 3 1 0 1 3
%e 1 1 3 0 1 1 1 0 3 0 2 2 3 1 0 3 1 3 1 0
%Y Column 1 of A235301.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 05 2014
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