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 A303407 #4 Apr 23 2018 10:39:43 %S A303407 3,27,100,547,4013,21361,115770,803911,4667376,27684643,182192785, %T A303407 1120872960,6916763577,44766799474,282088259954,1776639929407, %U A303407 11435967743483,72802740854480,463125006110247,2975736132751591 %N A303407 Number of nX5 0..1 arrays with every element equal to 1, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A303407 Column 5 of A303410. %H A303407 R. H. Hardin, <a href="/A303407/b303407.txt">Table of n, a(n) for n = 1..210</a> %e A303407 Some solutions for n=5 %e A303407 ..0..1..0..1..0. .0..1..0..1..1. .0..1..0..1..1. .0..0..1..0..1 %e A303407 ..0..0..1..0..0. .1..0..0..0..1. .0..0..1..0..0. .1..1..1..1..0 %e A303407 ..1..1..0..1..1. .1..1..0..1..0. .1..1..0..1..0. .1..1..1..1..1 %e A303407 ..0..1..0..1..0. .0..0..0..0..1. .1..1..1..1..0. .0..0..1..0..0 %e A303407 ..0..0..0..0..0. .1..1..0..1..1. .0..0..1..0..0. .0..1..1..1..0 %Y A303407 Cf. A303410. %K A303407 nonn %O A303407 1,1 %A A303407 _R. H. Hardin_, Apr 23 2018