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 A301610 #4 Mar 24 2018 11:38:56 %S A301610 1,11,62,367,2131,12467,72758,425003,2481842,14494425,84647239, %T A301610 494344466,2886987133,16860117364,98463698698,575031667957, %U A301610 3358206190785,19612048586036,114535089777733,668889165654501,3906337494564368 %N A301610 Number of nX3 0..1 arrays with every element equal to 1, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero. %C A301610 Column 3 of A301615. %H A301610 R. H. Hardin, <a href="/A301610/b301610.txt">Table of n, a(n) for n = 1..210</a> %F A301610 Empirical: a(n) = 4*a(n-1) +12*a(n-2) -5*a(n-3) -14*a(n-4) +14*a(n-6) +4*a(n-7) -3*a(n-8) -5*a(n-9) +a(n-10) %e A301610 Some solutions for n=5 %e A301610 ..0..0..1. .0..1..0. .0..1..0. .0..1..1. .0..0..0. .0..1..1. .0..0..0 %e A301610 ..1..1..1. .0..1..0. .0..1..0. .0..1..0. .1..0..0. .0..0..1. .0..1..1 %e A301610 ..1..0..1. .1..1..0. .0..0..0. .1..0..0. .1..1..1. .1..0..1. .0..0..1 %e A301610 ..1..0..1. .1..0..0. .1..1..0. .1..0..1. .0..1..1. .1..0..1. .1..1..0 %e A301610 ..1..0..1. .1..1..1. .1..1..0. .1..0..1. .0..0..1. .0..0..0. .1..1..0 %Y A301610 Cf. A301615. %K A301610 nonn %O A301610 1,2 %A A301610 _R. H. Hardin_, Mar 24 2018