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 A283037 #4 Feb 27 2017 08:55:38 %S A283037 1,16,119,818,5065,30378,175963,997302,5559013,30578068,166427637, %T A283037 897975464,4809947903,25605505484,135587794041,714668815274, %U A283037 3751742509465,19624971865578,102330051488077,532058283113570 %N A283037 Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element. %C A283037 Column 3 of A283042. %H A283037 R. H. Hardin, <a href="/A283037/b283037.txt">Table of n, a(n) for n = 1..210</a> %F A283037 Empirical: a(n) = 4*a(n-1) +16*a(n-2) -154*a(n-4) -470*a(n-5) -644*a(n-6) -306*a(n-7) +401*a(n-8) +700*a(n-9) +315*a(n-10) -82*a(n-11) -168*a(n-12) -104*a(n-13) -11*a(n-14) +14*a(n-15) +5*a(n-16) +2*a(n-17) -a(n-18) %e A283037 Some solutions for n=4 %e A283037 ..0..0..0. .1..0..0. .1..0..0. .0..1..1. .0..0..0. .1..0..1. .0..0..1 %e A283037 ..0..0..0. .0..0..1. .0..0..0. .1..0..0. .0..0..1. .0..1..0. .1..0..1 %e A283037 ..0..1..1. .0..1..0. .0..1..0. .0..0..0. .1..0..1. .1..0..0. .1..1..0 %e A283037 ..0..0..1. .0..1..1. .1..1..1. .1..1..1. .1..1..0. .1..1..0. .1..0..0 %Y A283037 Cf. A283042. %K A283037 nonn %O A283037 1,2 %A A283037 _R. H. Hardin_, Feb 27 2017