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 A302003 #4 Mar 30 2018 12:32:58 %S A302003 0,89,155,530,17800,100176,1366374,12824770,133115004,1366157014, %T A302003 13941336537,143149041167,1463519003210,14995308550903, %U A302003 153525291778069,1572142108724428,16098534802420026,164847528194904576 %N A302003 Number of 6Xn 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A302003 Row 6 of A301999. %H A302003 R. H. Hardin, <a href="/A302003/b302003.txt">Table of n, a(n) for n = 1..210</a> %e A302003 Some solutions for n=5 %e A302003 ..0..0..1..1..1. .0..0..0..0..1. .0..0..0..0..1. .0..0..1..0..0 %e A302003 ..0..0..0..1..0. .1..1..0..1..1. .1..1..0..1..0. .0..1..1..1..0 %e A302003 ..1..1..1..0..1. .0..0..0..1..1. .0..0..1..0..1. .0..0..0..0..0 %e A302003 ..0..0..1..1..1. .0..0..0..1..0. .1..1..0..1..1. .1..1..0..1..1 %e A302003 ..0..0..1..0..0. .0..1..1..0..1. .0..0..0..1..0. .1..1..1..0..1 %e A302003 ..0..0..0..1..1. .1..0..0..1..1. .0..1..1..0..0. .0..0..0..1..1 %Y A302003 Cf. A301999. %K A302003 nonn %O A302003 1,2 %A A302003 _R. H. Hardin_, Mar 30 2018