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 A302725 #6 Mar 15 2023 14:59:29 %S A302725 3,27,74,287,1307,4491,17828,80293,304958,1254491,5534905,22489246, %T A302725 94732609,413955598,1740468900,7436093945,32346857005,138259463124, %U A302725 595133929409,2583681234015,11128738383880,48080514602454 %N A302725 Number of n X 5 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302725 Column 5 of A302728. %H A302725 R. H. Hardin, <a href="/A302725/b302725.txt">Table of n, a(n) for n = 1..210</a> %e A302725 Some solutions for n=5 %e A302725 ..0..0..1..0..0. .0..1..0..0..0. .0..0..1..0..1. .0..0..0..0..1 %e A302725 ..0..1..1..1..1. .0..0..1..1..1. .0..1..1..1..0. .0..1..0..1..1 %e A302725 ..1..0..1..0..0. .0..1..1..1..1. .0..0..0..0..1. .1..1..1..1..1 %e A302725 ..0..1..1..1..1. .1..1..1..0..1. .1..0..0..0..0. .1..0..1..0..0 %e A302725 ..0..0..1..0..0. .1..0..0..1..0. .0..1..1..1..0. .0..1..0..1..1 %Y A302725 Cf. A302728. %K A302725 nonn %O A302725 1,1 %A A302725 _R. H. Hardin_, Apr 12 2018