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 A250966 #7 Jul 23 2025 12:55:09 %S A250966 14,308,22048,5089900,3794909318,9135168475316,71001116832347962, %T A250966 1781714118279963697630,144355770055582148091515150, %U A250966 37761829882206405363232456330430,31892938416369811765366547510541575588 %N A250966 Number of (n+1)X(n+1) 0..1 arrays with no 2X2 subblock having the sum of its diagonal elements less than the absolute difference of its antidiagonal elements. %C A250966 Diagonal of A250973 %H A250966 R. H. Hardin, <a href="/A250966/b250966.txt">Table of n, a(n) for n = 1..14</a> %e A250966 Some solutions for n=3 %e A250966 ..1..1..1..0....0..1..0..1....0..1..0..0....0..1..1..0....0..0..1..1 %e A250966 ..0..0..1..0....0..1..1..1....0..1..0..0....1..0..1..1....1..1..1..1 %e A250966 ..0..1..1..0....1..1..0..1....1..0..1..1....0..0..1..1....1..0..1..0 %e A250966 ..0..1..1..0....1..1..0..1....1..0..1..0....1..1..0..0....1..1..0..0 %K A250966 nonn %O A250966 1,1 %A A250966 _R. H. Hardin_, Nov 29 2014