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 A303085 #4 Apr 18 2018 12:21:48 %S A303085 4,2,32,29,258,432,2525,6313,30188,97855,428478,1605301,6821375, %T A303085 27390903,115569231,478335810,2017576268,8457463080,35707225807, %U A303085 150472100292,635822248364,2685274511197,11352580693193,47989709554314 %N A303085 Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A303085 Row 3 of A303084. %H A303085 R. H. Hardin, <a href="/A303085/b303085.txt">Table of n, a(n) for n = 1..210</a> %F A303085 Empirical: a(n) = 7*a(n-1) -2*a(n-2) -67*a(n-3) +80*a(n-4) +187*a(n-5) -202*a(n-6) -298*a(n-7) +122*a(n-8) +213*a(n-9) +122*a(n-10) +126*a(n-11) -63*a(n-12) -416*a(n-13) +152*a(n-14) +20*a(n-15) -21*a(n-16) +9*a(n-17) for n>18 %e A303085 Some solutions for n=5 %e A303085 ..0..0..1..1..1. .0..0..0..1..1. .0..1..1..1..0. .0..0..1..0..0 %e A303085 ..1..0..0..1..1. .0..0..1..1..1. .0..1..1..1..0. .1..0..0..0..0 %e A303085 ..0..0..1..1..0. .0..0..1..1..0. .1..1..1..1..0. .1..0..0..0..1 %Y A303085 Cf. A303084. %K A303085 nonn %O A303085 1,1 %A A303085 _R. H. Hardin_, Apr 18 2018