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 A297874 #4 Jan 07 2018 11:30:48 %S A297874 0,13,3,68,231,887,3307,13910,55501,228947,947582,3930953,16243210, %T A297874 67305782,278635282,1154097789,4780226279,19802856358,82032779562, %U A297874 339845971291,1407890373170,5832655811595,24163797280825,100107714077232 %N A297874 Number of nX6 0..1 arrays with every element equal to 2, 3 or 5 king-move adjacent elements, with upper left element zero. %C A297874 Column 6 of A297876. %H A297874 R. H. Hardin, <a href="/A297874/b297874.txt">Table of n, a(n) for n = 1..210</a> %e A297874 Some solutions for n=7 %e A297874 ..0..0..0..0..1..1. .0..0..1..1..1..1. .0..0..1..0..0..1. .0..0..1..0..1..1 %e A297874 ..0..1..1..0..0..1. .0..1..0..0..0..1. .0..1..1..0..1..1. .0..1..0..1..0..1 %e A297874 ..0..1..0..1..0..1. .1..0..1..1..0..1. .1..0..0..0..0..1. .0..1..1..0..0..1 %e A297874 ..0..1..0..1..1..1. .1..0..1..0..1..1. .0..1..1..1..1..0. .0..1..0..1..0..1 %e A297874 ..0..1..1..0..0..1. .1..0..1..0..0..0. .0..0..0..0..0..1. .0..1..0..1..0..1 %e A297874 ..0..1..0..1..1..0. .1..0..1..0..1..0. .1..1..1..0..1..1. .1..0..1..0..0..1 %e A297874 ..0..0..1..0..0..0. .1..1..0..1..1..1. .1..1..1..0..0..1. .1..1..0..0..1..1 %Y A297874 Cf. A297876. %K A297874 nonn %O A297874 1,2 %A A297874 _R. H. Hardin_, Jan 07 2018