Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #10 Jun 18 2022 23:38:37
%S 744,1132,1736,3184,5784,12328,25592,60856,138744,356632,864056,
%T 2342104,5889144,16525528,42475832,121851736,317293944,923151832,
%U 2422801976,7113966424,18762768504,55430893528,146666831672,435125968216
%N Number of (n+1) X (4+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="/A235294/b235294.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*(186 - 275*x - 3577*x^2 + 5285*x^3 + 23807*x^4 - 34904*x^5 - 64146*x^6 + 92340*x^7 + 59328*x^8 - 82944*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 3 0 3 1 0 3 0 0 0 0 3 2 0 2 3 3 0 3 3
%e 0 0 0 0 1 3 3 3 0 3 0 0 2 3 2 0 3 3 3 0
%e 0 3 0 3 1 3 0 3 3 3 0 3 2 0 2 3 3 0 3 3
%e 1 1 1 1 2 0 0 0 3 0 0 0 2 3 2 0 3 3 3 0
%e 0 3 0 3 1 3 0 3 3 3 0 3 2 0 2 0 0 3 0 0
%e 2 2 2 2 3 3 3 3 0 3 0 0 2 3 2 0 3 3 3 0
%Y Column 4 of A235301.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 05 2014