This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A250967 #10 Nov 24 2018 08:11:46 %S A250967 49,308,1945,12281,77537,489543,3090834,19514643,123209858,777911692, %T A250967 4911511266,31009873218,195787443967,1236145757310,7804669708967, %U A250967 49276445682891,311117342524943,1964305653103961,12402062409962968 %N A250967 Number of (n+1) X (2+1) 0..1 arrays with no 2 X 2 subblock having the sum of its diagonal elements less than the absolute difference of its antidiagonal elements. %H A250967 R. H. Hardin, <a href="/A250967/b250967.txt">Table of n, a(n) for n = 1..210</a> %F A250967 Empirical: a(n) = 8*a(n-1) - 13*a(n-2) + 17*a(n-3) - 14*a(n-4) + 3*a(n-5). %F A250967 Empirical g.f.: x*(49 - 84*x + 118*x^2 - 108*x^3 + 24*x^4) / ((1 - x)*(1 - 7*x + 6*x^2 - 11*x^3 + 3*x^4)). - _Colin Barker_, Nov 24 2018 %e A250967 Some solutions for n=4: %e A250967 1 1 0 0 1 0 1 0 1 1 1 0 1 0 1 1 1 1 1 1 1 %e A250967 1 0 1 1 0 0 1 1 1 1 1 1 1 0 1 0 0 1 0 0 0 %e A250967 0 1 1 0 1 1 1 0 1 1 1 1 0 1 1 0 1 0 1 1 1 %e A250967 0 1 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 1 1 1 %e A250967 1 0 1 1 0 0 1 0 1 1 1 0 0 1 0 1 1 0 0 0 0 %Y A250967 Column 2 of A250973. %K A250967 nonn %O A250967 1,1 %A A250967 _R. H. Hardin_, Nov 29 2014