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 A240516 #6 Oct 01 2021 17:21:10 %S A240516 8,21,73,326,1376,6205,28942,135093,636475,3024792,14429369,69010353, %T A240516 330906118,1589431389,7642628408,36779710534,177110221193, %U A240516 853219818189,4111568990816,19817506062480,95533854083563,460587995304966 %N A240516 Number of n X 5 0..1 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..1 introduced in row major order. %C A240516 Column 5 of A240519. %H A240516 R. H. Hardin, <a href="/A240516/b240516.txt">Table of n, a(n) for n = 1..210</a> %e A240516 Some solutions for n=4 %e A240516 ..0..1..1..0..1....0..1..1..1..0....0..0..0..1..0....0..1..0..1..0 %e A240516 ..1..0..0..0..0....1..0..1..0..0....1..0..1..0..1....1..1..1..0..1 %e A240516 ..0..1..0..1..1....0..1..0..1..0....0..1..0..0..0....0..1..0..1..1 %e A240516 ..1..0..1..0..0....1..0..1..1..1....1..1..1..0..1....1..0..1..0..1 %Y A240516 Cf. A240519. %K A240516 nonn %O A240516 1,1 %A A240516 _R. H. Hardin_, Apr 06 2014