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 A303678 #4 Apr 28 2018 09:20:38 %S A303678 5,17,15,28,44,64,90,132,204,312,466,688,1024,1540,2318,3472,5184, %T A303678 7748,11606,17396,26052,38984,58338,87340,130788,195824,293146,438824, %U A303678 656952,983564,1472534,2204504,3300280,4940796,7396894,11073932,16578716 %N A303678 Number of nX4 0..1 arrays with every element unequal to 0, 1 or 3 king-move adjacent elements, with upper left element zero. %C A303678 Column 4 of A303682. %H A303678 R. H. Hardin, <a href="/A303678/b303678.txt">Table of n, a(n) for n = 1..210</a> %F A303678 Empirical: a(n) = a(n-1) +a(n-4) +a(n-5) for n>8 %e A303678 Some solutions for n=5 %e A303678 ..0..0..0..1. .0..0..0..0. .0..1..1..1. .0..1..1..1. .0..1..1..1 %e A303678 ..0..0..0..0. .0..0..0..0. .0..0..1..1. .1..1..1..1. .1..1..1..1 %e A303678 ..1..0..0..0. .0..0..0..1. .0..0..0..1. .1..1..1..1. .1..1..1..1 %e A303678 ..1..1..0..0. .0..0..1..1. .0..0..0..0. .1..1..1..1. .0..1..1..1 %e A303678 ..1..1..1..0. .0..1..1..1. .1..0..0..0. .0..1..1..0. .0..0..1..1 %Y A303678 Cf. A303682. %K A303678 nonn %O A303678 1,1 %A A303678 _R. H. Hardin_, Apr 28 2018