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 A303523 #4 Apr 25 2018 12:39:41 %S A303523 13,113,286,1875,13031,102779,965150,9961980,109395622,1249312308, %T A303523 14535068668,170908188530,2021484478581,23981853993648, %U A303523 284987683948763,3389805878799915,40340446531700113,480206820275333547 %N A303523 Number of nX6 0..1 arrays with every element equal to 0, 1, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A303523 Column 6 of A303525. %H A303523 R. H. Hardin, <a href="/A303523/b303523.txt">Table of n, a(n) for n = 1..210</a> %e A303523 Some solutions for n=5 %e A303523 ..0..1..0..1..0..1. .0..1..1..0..1..0. .0..1..1..1..0..0. .0..1..0..1..0..1 %e A303523 ..0..0..1..1..0..1. .1..1..1..1..0..0. .1..1..1..1..1..1. .1..1..0..1..1..0 %e A303523 ..1..1..1..1..1..0. .0..1..1..1..1..0. .0..1..1..0..0..1. .1..1..1..1..1..1 %e A303523 ..0..0..1..1..1..1. .0..1..0..1..1..0. .0..0..0..0..0..0. .0..1..0..1..1..1 %e A303523 ..1..1..1..1..1..0. .0..1..0..1..0..1. .0..1..1..0..0..1. .0..1..1..1..1..0 %Y A303523 Cf. A303525. %K A303523 nonn %O A303523 1,1 %A A303523 _R. H. Hardin_, Apr 25 2018