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 A300806 #4 Mar 13 2018 07:51:28 %S A300806 4,29,170,1004,5908,34836,205369,1210811,7138574,42087052,248133414, %T A300806 1462925107,8624996341,50850561207,299800657068,1767540650375, %U A300806 10420924293471,61438849007573,362226234550315,2135584359343994 %N A300806 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A300806 Column 3 of A300811. %H A300806 R. H. Hardin, <a href="/A300806/b300806.txt">Table of n, a(n) for n = 1..210</a> %F A300806 Empirical: a(n) = 5*a(n-1) +7*a(n-2) -10*a(n-3) -a(n-4) +4*a(n-5) -17*a(n-6) +2*a(n-7) +5*a(n-8) -6*a(n-9) +5*a(n-10) -2*a(n-12) +a(n-13) %e A300806 Some solutions for n=5 %e A300806 ..0..1..1. .0..1..1. .0..1..0. .0..1..0. .0..1..1. .0..1..0. .0..0..0 %e A300806 ..1..0..1. .1..0..1. .0..0..0. .1..0..0. .1..0..0. .1..0..0. .0..1..0 %e A300806 ..1..1..1. .0..0..1. .1..1..1. .0..1..0. .0..1..1. .1..1..1. .0..1..1 %e A300806 ..0..0..1. .1..1..1. .1..0..1. .0..1..0. .1..1..0. .0..0..1. .0..1..0 %e A300806 ..0..0..0. .0..0..0. .0..0..1. .1..1..0. .0..0..0. .0..1..0. .0..0..0 %Y A300806 Cf. A300811. %K A300806 nonn %O A300806 1,1 %A A300806 _R. H. Hardin_, Mar 13 2018