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 A318071 #4 Aug 15 2018 13:18:18 %S A318071 8,20,41,73,149,372,861,2016,4901,11698,27986,67359,161518,387556, %T A318071 930666,2233451,5360842,12868595,30887501,74139733,177960357, %U A318071 427157604,1025312853,2461074852,5907342192,14179472548,34035173339,81695041734 %N A318071 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A318071 Column 4 of A318075. %H A318071 R. H. Hardin, <a href="/A318071/b318071.txt">Table of n, a(n) for n = 1..210</a> %F A318071 Empirical: a(n) = 2*a(n-1) +a(n-2) +2*a(n-3) -3*a(n-4) -5*a(n-5) -2*a(n-7) +7*a(n-8) -a(n-9) -2*a(n-10) +8*a(n-11) -3*a(n-12) -a(n-13) -3*a(n-14) -3*a(n-15) +4*a(n-16) +a(n-17) -a(n-18) for n>21 %e A318071 Some solutions for n=5 %e A318071 ..0..0..0..0. .0..1..1..1. .0..1..0..0. .0..1..1..1. .0..0..0..0 %e A318071 ..0..0..0..0. .1..1..1..1. .1..1..0..0. .1..1..1..1. .0..0..1..0 %e A318071 ..0..0..0..0. .1..1..1..1. .1..1..0..0. .0..0..0..0. .0..1..0..0 %e A318071 ..1..1..1..1. .1..1..1..1. .1..1..0..0. .0..0..0..0. .0..0..0..0 %e A318071 ..1..1..1..0. .1..1..1..1. .1..1..0..0. .0..0..0..1. .0..0..0..1 %Y A318071 Cf. A318075. %K A318071 nonn %O A318071 1,1 %A A318071 _R. H. Hardin_, Aug 15 2018