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 A301911 #4 Mar 28 2018 16:13:04 %S A301911 64,1,117,65,196,1999,8781,104732,770376,7398173,75183520,712349998, %T A301911 7178506389,72042620797,721879978606,7250047119979,72777298549367, %U A301911 730558484014599,7332580130417856,73594615185044259,738663477116841069 %N A301911 Number of 7Xn 0..1 arrays with every element equal to 0, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A301911 Row 7 of A301906. %H A301911 R. H. Hardin, <a href="/A301911/b301911.txt">Table of n, a(n) for n = 1..210</a> %e A301911 Some solutions for n=5 %e A301911 ..0..1..1..0..0. .0..1..1..0..0. .0..1..1..0..0. .0..1..1..0..1 %e A301911 ..1..1..0..0..1. .1..1..0..0..1. .1..1..0..0..1. .1..1..1..0..1 %e A301911 ..1..1..1..0..1. .1..1..0..0..0. .1..1..1..0..1. .0..1..1..0..1 %e A301911 ..1..1..1..0..0. .1..1..1..0..0. .0..1..1..0..0. .0..1..1..0..0 %e A301911 ..0..1..0..0..0. .1..1..0..0..1. .0..1..0..0..1. .1..1..0..0..1 %e A301911 ..1..1..1..0..0. .0..1..1..0..0. .1..1..1..0..0. .0..1..1..0..0 %e A301911 ..1..1..0..0..1. .1..1..0..0..1. .1..1..0..0..1. .1..1..0..0..1 %Y A301911 Cf. A301906. %K A301911 nonn %O A301911 1,1 %A A301911 _R. H. Hardin_, Mar 28 2018