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 A298137 #4 Jan 13 2018 11:13:51 %S A298137 0,13,3,68,242,917,3417,14533,58845,244155,1024766,4297121,17950575, %T A298137 75199021,314755111,1317874937,5519233903,23115442566,96811939884, %U A298137 405493370013,1698383143180,7113695019637,29796021993208,124802553668569 %N A298137 Number of nX6 0..1 arrays with every element equal to 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero. %C A298137 Column 6 of A298139. %H A298137 R. H. Hardin, <a href="/A298137/b298137.txt">Table of n, a(n) for n = 1..210</a> %e A298137 Some solutions for n=7 %e A298137 ..0..0..1..1..0..0. .0..0..0..0..0..1. .0..0..0..1..1..0. .0..1..1..0..1..1 %e A298137 ..0..1..0..1..1..0. .0..1..1..0..1..1. .0..0..0..1..0..0. .0..0..1..0..0..1 %e A298137 ..1..1..0..1..1..1. .0..1..0..1..0..0. .1..1..1..1..1..0. .0..1..1..1..1..0 %e A298137 ..0..1..0..0..0..1. .0..1..0..1..0..1. .1..0..0..0..0..1. .1..0..0..0..0..1 %e A298137 ..0..0..0..0..1..0. .0..1..0..0..1..1. .0..1..0..1..1..0. .1..0..1..1..1..0 %e A298137 ..1..1..0..1..1..0. .0..1..0..1..0..1. .0..1..0..0..1..0. .0..1..1..0..0..1 %e A298137 ..1..0..0..1..0..0. .0..0..1..1..0..0. .0..0..1..1..0..0. .0..0..0..0..1..1 %Y A298137 Cf. A298139. %K A298137 nonn %O A298137 1,2 %A A298137 _R. H. Hardin_, Jan 13 2018