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 A299649 #4 Feb 15 2018 14:38:37 %S A299649 4,32,247,1924,14981,116654,908360,7073213,55077652,428878329, %T A299649 3339587196,26004677512,202493066595,1576771794248,12277997133149, %U A299649 95606234301950,744466050795960,5797003771085993,45140074132400664,351496458022297409 %N A299649 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero. %C A299649 Column 3 of A299654. %H A299649 R. H. Hardin, <a href="/A299649/b299649.txt">Table of n, a(n) for n = 1..210</a> %F A299649 Empirical: a(n) = 7*a(n-1) +5*a(n-2) +9*a(n-3) -a(n-4) -6*a(n-5) %e A299649 Some solutions for n=5 %e A299649 ..0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..1. .0..0..1. .0..1..0 %e A299649 ..0..0..1. .0..1..1. .0..1..0. .1..0..0. .0..1..0. .0..1..1. .1..0..0 %e A299649 ..0..0..1. .1..1..1. .1..1..1. .0..1..0. .0..1..1. .0..0..0. .1..1..0 %e A299649 ..1..0..1. .0..1..0. .1..1..0. .1..0..0. .0..1..1. .1..0..1. .0..1..0 %e A299649 ..1..1..0. .1..1..0. .0..0..1. .0..0..0. .1..0..1. .0..0..1. .1..0..1 %Y A299649 Cf. A299654. %K A299649 nonn %O A299649 1,1 %A A299649 _R. H. Hardin_, Feb 15 2018