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 A301793 #4 Mar 26 2018 16:44:10 %S A301793 8,34,24,32,45,66,100,155,244,388,621,998,1608,2595,4192,6776,10957, %T A301793 17722,28668,46379,75036,121404,196429,317822,514240,832051,1346280, %U A301793 2178320,3524589,5702898,9227476,14930363,24157828,39088180,63245997 %N A301793 Number of 4Xn 0..1 arrays with every element equal to 0 or 1 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A301793 Row 4 of A301790. %H A301793 R. H. Hardin, <a href="/A301793/b301793.txt">Table of n, a(n) for n = 1..210</a> %F A301793 Empirical: a(n) = 2*a(n-1) -a(n-3) for n>5 %e A301793 Some solutions for n=5 %e A301793 ..0..1..0..1..0. .0..1..1..0..1. .0..0..1..0..1. .0..0..1..0..1 %e A301793 ..1..0..1..0..1. .0..0..1..0..0. .1..0..1..0..0. .1..0..1..0..1 %e A301793 ..1..0..1..0..1. .1..0..1..1..0. .1..0..1..1..0. .1..0..1..0..1 %e A301793 ..0..1..0..1..0. .1..0..0..1..1. .1..0..0..1..1. .0..1..0..1..0 %Y A301793 Cf. A301790. %K A301793 nonn %O A301793 1,1 %A A301793 _R. H. Hardin_, Mar 26 2018