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 A284219 #6 Apr 05 2020 22:44:11 %S A284219 10,143,3214,85887,2417194,69938626,2058141264,61304713234, %T A284219 1842647045686,55774782577154,1697707702343462,51912416104327610, %U A284219 1593418341131944098,49066300496202571019,1515066051729449019246,46893719654238123775675 %N A284219 Number of n X 5 0..1 arrays with the number of 1's horizontally or antidiagonally adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero. %C A284219 Column 5 of A284222. %H A284219 R. H. Hardin, <a href="/A284219/b284219.txt">Table of n, a(n) for n = 1..210</a> %e A284219 Some solutions for n=4 %e A284219 ..0..1..0..1..0. .0..1..1..0..1. .0..0..0..1..0. .0..0..1..0..1 %e A284219 ..1..0..0..1..1. .0..1..1..0..0. .1..1..1..1..0. .1..0..0..1..0 %e A284219 ..1..0..1..1..0. .1..0..1..1..0. .0..0..1..1..1. .1..0..0..1..0 %e A284219 ..1..0..0..1..1. .1..0..0..0..1. .1..0..0..0..0. .1..1..0..1..1 %Y A284219 Cf. A284222. %K A284219 nonn %O A284219 1,1 %A A284219 _R. H. Hardin_, Mar 23 2017