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 A302422 #4 Apr 07 2018 17:18:18 %S A302422 3,9,11,21,51,93,207,517,1007,2333,5847,11781,27055,66861,137895, %T A302422 314197,766367,1610429,3649239,8799333,18772687,42381645,101181063, %U A302422 218513269,492148223,1164905693,2540589879,5713965957,13425837103,29512490349 %N A302422 Number of nX3 0..1 arrays with every element equal to 0, 1, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302422 Column 3 of A302427. %H A302422 R. H. Hardin, <a href="/A302422/b302422.txt">Table of n, a(n) for n = 1..210</a> %F A302422 Empirical: a(n) = a(n-1) +10*a(n-3) -8*a(n-4) for n>9 %e A302422 Some solutions for n=5 %e A302422 ..0..0..1. .0..0..1. .0..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..1 %e A302422 ..0..1..0. .0..1..0. .0..1..0. .0..1..0. .1..1..0. .1..0..1. .0..0..0 %e A302422 ..1..1..1. .0..1..0. .0..1..0. .0..1..0. .1..1..1. .1..0..1. .0..1..0 %e A302422 ..1..1..0. .0..1..1. .1..1..0. .0..1..0. .0..1..0. .1..0..1. .0..1..0 %e A302422 ..0..1..0. .0..1..0. .0..1..0. .1..0..0. .1..0..0. .1..0..1. .0..0..1 %Y A302422 Cf. A302427. %K A302422 nonn %O A302422 1,1 %A A302422 _R. H. Hardin_, Apr 07 2018