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 A298915 #4 Jan 29 2018 07:44:27 %S A298915 1,5,5,6,9,14,24,44,81,156,306,602,1192,2370,4720,9415,18797,37547, %T A298915 75032,149981,299846,599534,1198852,2397405,4794400,9588236,19175692, %U A298915 38350310,76699140,153396236,306789653,613575417,1227145465,2454283522,4908556821 %N A298915 Number of nX6 0..1 arrays with every element equal to 0, 3, 5, 7 or 8 king-move adjacent elements, with upper left element zero. %C A298915 Column 6 of A298917. %H A298915 R. H. Hardin, <a href="/A298915/b298915.txt">Table of n, a(n) for n = 1..210</a> %F A298915 Empirical: a(n) = 3*a(n-1) -2*a(n-2) +a(n-3) -2*a(n-4) -a(n-7) +2*a(n-8) for n>9 %e A298915 Some solutions for n=5 %e A298915 ..0..0..0..0..0..0. .0..0..0..1..1..1. .0..0..0..0..0..0. .0..0..1..1..0..0 %e A298915 ..0..0..0..0..0..0. .0..0..0..1..1..1. .0..0..0..0..0..0. .0..0..1..1..0..0 %e A298915 ..0..0..0..0..0..0. .0..0..0..1..1..1. .0..0..0..1..0..0. .0..0..1..1..0..0 %e A298915 ..1..1..1..1..1..1. .0..0..0..1..1..1. .0..0..0..0..0..0. .0..0..1..1..0..0 %e A298915 ..1..1..1..1..1..1. .0..0..0..1..1..1. .0..0..0..0..0..0. .0..0..1..1..0..0 %Y A298915 Cf. A298917. %K A298915 nonn %O A298915 1,2 %A A298915 _R. H. Hardin_, Jan 29 2018