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 A301908 #4 Mar 28 2018 16:10:55 %S A301908 8,1,7,5,8,40,96,316,1078,3831,13331,46127,161362,564617,1975369, %T A301908 6914911,24216868,84826850,297130258,1040826424,3646117344, %U A301908 12772898193,44745724111,156753135377,549139791596,1923758528089,6739359943131 %N A301908 Number of 4Xn 0..1 arrays with every element equal to 0, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A301908 Row 4 of A301906. %H A301908 R. H. Hardin, <a href="/A301908/b301908.txt">Table of n, a(n) for n = 1..210</a> %e A301908 Some solutions for n=5 %e A301908 ..0..1..1..0..0. .0..1..1..0..0. .0..1..1..0..0. .0..1..1..0..0 %e A301908 ..1..1..0..0..1. .1..1..0..0..0. .1..1..0..0..0. .1..1..0..0..1 %e A301908 ..1..1..1..0..0. .0..1..1..0..0. .1..1..1..0..0. .0..1..1..0..0 %e A301908 ..1..1..0..0..1. .1..1..0..0..1. .1..1..0..0..1. .1..1..0..0..1 %Y A301908 Cf. A301906. %K A301908 nonn %O A301908 1,1 %A A301908 _R. H. Hardin_, Mar 28 2018