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 A231521 #6 Jul 23 2025 06:33:42 %S A231521 21,1069,25556,680302,17572772,451200772,11683058939,302190345444, %T A231521 7806399525348,201765495180944,5215449996133433,134798889001969231, %U A231521 3484039440752712049,90050899758881308054,2327507605574582278738 %N A231521 Number of nX6 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors. %C A231521 Column 6 of A231523 %H A231521 R. H. Hardin, <a href="/A231521/b231521.txt">Table of n, a(n) for n = 1..210</a> %e A231521 Some solutions for n=3 %e A231521 ..0..0..0..0..0..0....0..0..0..0..1..0....0..1..1..0..0..1....0..1..1..0..1..0 %e A231521 ..0..0..0..0..0..0....0..0..0..0..0..0....1..0..1..0..0..1....1..0..0..1..0..0 %e A231521 ..0..1..1..1..0..0....1..0..1..1..0..1....0..0..0..0..0..0....1..1..0..0..0..0 %K A231521 nonn %O A231521 1,1 %A A231521 _R. H. Hardin_, Nov 10 2013