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 A303470 #4 Apr 24 2018 10:44:18 %S A303470 4,32,170,948,5237,29009,160590,888993,4921496,27244949,150826626, %T A303470 834967061,4622327859,25588933014,141658809728,784214751260, %U A303470 4341366231543,24033545332699,133048277989004,736547356196655 %N A303470 Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A303470 Row 3 of A303469. %H A303470 R. H. Hardin, <a href="/A303470/b303470.txt">Table of n, a(n) for n = 1..210</a> %F A303470 Empirical: a(n) = 3*a(n-1) +15*a(n-2) -32*a(n-4) +5*a(n-5) +53*a(n-6) -14*a(n-7) -10*a(n-8) +19*a(n-9) -5*a(n-10) +8*a(n-11) +a(n-12) -4*a(n-13) -2*a(n-14) for n>15 %e A303470 Some solutions for n=5 %e A303470 ..0..0..1..0..1. .0..1..0..0..0. .0..0..1..0..0. .0..1..0..1..1 %e A303470 ..0..0..0..0..1. .1..0..1..1..1. .1..1..0..1..0. .1..1..0..1..0 %e A303470 ..0..1..0..0..1. .1..0..1..0..0. .0..1..1..0..1. .0..0..1..1..1 %Y A303470 Cf. A303469. %K A303470 nonn %O A303470 1,1 %A A303470 _R. H. Hardin_, Apr 24 2018