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 A303103 #4 Apr 18 2018 12:39:49 %S A303103 0,11,77,431,2913,19393,128921,857789,5706297,37961366,252538085, %T A303103 1680012401,11176296913,74350419884,494616846377,3290443118074, %U A303103 21889703025083,145621450295042,968748034460686,6444605189965405 %N A303103 Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A303103 Row 3 of A303102. %H A303103 R. H. Hardin, <a href="/A303103/b303103.txt">Table of n, a(n) for n = 1..210</a> %F A303103 Empirical: a(n) = 5*a(n-1) +11*a(n-2) +a(n-4) -8*a(n-5) -a(n-6) -20*a(n-7) -2*a(n-8) -13*a(n-9) +3*a(n-10) -6*a(n-11) -5*a(n-12) +a(n-13) -2*a(n-14) for n>15 %e A303103 Some solutions for n=5 %e A303103 ..0..1..1..1..1. .0..0..1..1..0. .0..0..1..1..1. .0..0..1..0..0 %e A303103 ..1..0..1..0..0. .1..1..0..0..1. .0..0..0..1..0. .1..1..0..1..0 %e A303103 ..0..0..0..1..1. .0..0..0..1..1. .0..1..1..0..1. .1..1..0..0..1 %Y A303103 Cf. A303102. %K A303103 nonn %O A303103 1,2 %A A303103 _R. H. Hardin_, Apr 18 2018