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 A301909 #4 Mar 28 2018 16:11:44 %S A301909 16,1,16,10,12,92,320,1588,7234,34477,171770,861562,4318341,21575848, %T A301909 107657594,537357962,2682516710,13395048430,66897233633,334110946467, %U A301909 1668703731020,8334274683849,41625156594335,207894886362394 %N A301909 Number of 5Xn 0..1 arrays with every element equal to 0, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A301909 Row 5 of A301906. %H A301909 R. H. Hardin, <a href="/A301909/b301909.txt">Table of n, a(n) for n = 1..210</a> %e A301909 Some solutions for n=5 %e A301909 ..0..1..0..1..0. .0..1..1..0..1. .0..1..1..1..1. .0..1..1..0..1 %e A301909 ..0..1..0..1..0. .1..1..1..0..0. .1..1..0..1..1. .1..1..1..0..1 %e A301909 ..0..1..0..1..0. .0..1..0..0..0. .1..1..0..1..1. .0..1..1..0..1 %e A301909 ..0..1..0..1..0. .1..1..1..0..0. .1..1..0..1..1. .0..1..1..0..0 %e A301909 ..0..1..0..1..0. .1..1..0..0..1. .1..1..1..1..0. .1..1..0..0..1 %Y A301909 Cf. A301906. %K A301909 nonn %O A301909 1,1 %A A301909 _R. H. Hardin_, Mar 28 2018