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 A302960 #4 Apr 16 2018 11:51:43 %S A302960 4,29,154,833,4527,24602,133757,727293,3954552,21502829,116922075, %T A302960 635766762,3457004649,18797598113,102212699104,555785781065, %U A302960 3022108386151,16432841038810,89354263698021,485867567617493 %N A302960 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302960 Column 3 of A302965. %H A302960 R. H. Hardin, <a href="/A302960/b302960.txt">Table of n, a(n) for n = 1..210</a> %F A302960 Empirical: a(n) = 7*a(n-1) -7*a(n-2) -56*a(n-4) +64*a(n-5) for n>6 %e A302960 Some solutions for n=5 %e A302960 ..0..0..0. .0..0..0. .0..1..1. .0..1..0. .0..1..0. .0..0..0. .0..1..0 %e A302960 ..1..1..0. .0..1..1. .0..0..1. .1..1..0. .0..1..0. .0..1..1. .0..1..0 %e A302960 ..0..0..0. .0..1..1. .1..0..1. .0..0..0. .1..1..0. .1..1..0. .1..1..1 %e A302960 ..1..1..1. .1..0..0. .0..1..1. .1..0..1. .1..0..1. .1..0..0. .0..0..0 %e A302960 ..0..0..0. .1..0..1. .0..1..0. .1..1..0. .0..1..1. .1..1..1. .0..0..1 %Y A302960 Cf. A302965. %K A302960 nonn %O A302960 1,1 %A A302960 _R. H. Hardin_, Apr 16 2018