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 A303718 #6 May 12 2023 15:21:56 %S A303718 21,23,40,161,361,741,1592,3469,7416,15880,34193,73457,157645,338676, %T A303718 727589,1562584,3356196,7209121,15484337,33258365,71436088,153437805, %U A303718 329568008,707878984,1520453793,3265780153,7014565013,15066579716 %N A303718 Number of n X 7 0..1 arrays with every element unequal to 0, 1 or 5 king-move adjacent elements, with upper left element zero. %C A303718 Column 7 of A303719. %H A303718 R. H. Hardin, <a href="/A303718/b303718.txt">Table of n, a(n) for n = 1..210</a> %F A303718 Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -a(n-6) for n>9 %e A303718 Some solutions for n=5 %e A303718 ..0..0..1..0..0..0..0. .0..0..1..0..0..0..0. .0..1..0..0..0..0..0 %e A303718 ..0..0..0..0..0..0..0. .0..0..0..0..0..0..1. .0..0..0..0..0..0..1 %e A303718 ..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0 %e A303718 ..0..0..0..0..0..0..0. .1..0..0..0..0..0..0. .0..0..0..0..0..0..0 %e A303718 ..0..0..0..0..1..0..0. .0..0..0..0..0..0..0. .0..0..1..0..0..0..0 %Y A303718 Cf. A303719. %K A303718 nonn %O A303718 1,1 %A A303718 _R. H. Hardin_, Apr 29 2018