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 A301398 #4 Mar 20 2018 11:01:03 %S A301398 0,19,156,2619,49325,885003,16325745,299552320,5507220522, %T A301398 101241811692,1861266294856,34219577018840,629127370642307, %U A301398 11566583462993881,212652959829786846,3909650837047832782,71879414458502966455 %N A301398 Number of nX6 0..1 arrays with every element equal to 2, 3, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A301398 Column 6 of A301400. %H A301398 R. H. Hardin, <a href="/A301398/b301398.txt">Table of n, a(n) for n = 1..210</a> %e A301398 Some solutions for n=5 %e A301398 ..0..0..1..0..0..0. .0..0..1..1..1..1. .0..0..1..1..0..0. .0..0..1..1..0..0 %e A301398 ..0..1..1..0..0..0. .0..0..1..0..1..0. .0..0..1..1..0..0. .0..1..1..0..0..1 %e A301398 ..1..1..0..0..0..0. .1..1..0..0..0..0. .0..0..0..0..0..0. .0..1..1..0..1..1 %e A301398 ..1..1..1..0..0..1. .1..1..0..1..1..1. .0..1..1..1..0..1. .0..0..0..0..0..0 %e A301398 ..1..1..1..1..1..1. .1..0..0..1..1..1. .1..1..1..1..1..1. .0..0..0..0..0..0 %Y A301398 Cf. A301400. %K A301398 nonn %O A301398 1,2 %A A301398 _R. H. Hardin_, Mar 20 2018