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 A298257 #4 Jan 15 2018 14:58:39 %S A298257 0,13,7,72,238,895,3335,13980,55889,230402,953813,3957108,16359243, %T A298257 67815820,280896101,1164014899,4823739307,19992787735,82860456229, %U A298257 343442251791,1423487855696,5900154785814,24455403244104,101365322534618 %N A298257 Number of nX6 0..1 arrays with every element equal to 2, 3, 5 or 8 king-move adjacent elements, with upper left element zero. %C A298257 Column 6 of A298259. %H A298257 R. H. Hardin, <a href="/A298257/b298257.txt">Table of n, a(n) for n = 1..210</a> %e A298257 Some solutions for n=8 %e A298257 ..0..0..1..1..1..1. .0..0..0..0..1..1. .0..0..1..1..1..1. .0..0..1..1..0..0 %e A298257 ..0..1..0..0..0..1. .0..1..1..0..0..1. .0..1..1..0..0..1. .0..1..1..0..1..0 %e A298257 ..1..0..1..1..1..0. .1..0..1..1..1..0. .0..1..0..1..1..0. .1..0..0..0..1..0 %e A298257 ..1..1..0..0..0..1. .1..0..0..0..0..1. .0..1..0..0..1..0. .1..1..1..1..0..0 %e A298257 ..1..0..1..1..0..1. .0..1..1..1..0..1. .0..1..1..0..1..0. .0..0..0..0..1..0 %e A298257 ..1..0..0..1..0..1. .0..0..1..0..1..1. .0..0..1..0..1..0. .0..1..1..1..1..0 %e A298257 ..0..1..1..1..1..0. .1..1..0..1..1..0. .1..0..1..0..1..0. .1..0..0..0..0..1 %e A298257 ..0..0..0..0..0..0. .1..0..0..0..0..0. .1..1..0..1..0..0. .1..1..1..1..1..1 %Y A298257 Cf. A298259. %K A298257 nonn %O A298257 1,2 %A A298257 _R. H. Hardin_, Jan 15 2018