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 A231660 #6 Jul 23 2025 06:37:03 %S A231660 51,2163,144465,8300390,434469343,23632808750,1304771142134, %T A231660 71426776678405,3902799543486962,213611346097185990, %U A231660 11693195116075740433,639903225251107962333,35018805296966170944821,1916494358794580661283650 %N A231660 Number of nX5 0..2 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors. %C A231660 Column 5 of A231663 %H A231660 R. H. Hardin, <a href="/A231660/b231660.txt">Table of n, a(n) for n = 1..210</a> %e A231660 Some solutions for n=3 %e A231660 ..0..0..0..0..0....2..0..0..0..0....2..0..1..0..0....0..0..2..0..1 %e A231660 ..1..1..0..0..1....0..0..1..0..1....0..0..0..0..0....0..1..0..0..1 %e A231660 ..1..1..2..0..0....0..2..1..0..0....2..2..1..1..2....1..1..0..0..1 %K A231660 nonn %O A231660 1,1 %A A231660 _R. H. Hardin_, Nov 12 2013