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 A284225 #6 Apr 05 2020 22:48:03 %S A284225 8,62,467,6511,85887,1214427,17538010,258414316,3854276528, %T A284225 58011648676,879122723506,13394856893254,204995150323546, %U A284225 3148797878923546,48517163038369066,749553577633265717,11606806249286351346 %N A284225 Number of 4 X n 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 A284225 Row 4 of A284222. %H A284225 R. H. Hardin, <a href="/A284225/b284225.txt">Table of n, a(n) for n = 1..176</a> %e A284225 Some solutions for n=4 %e A284225 ..0..1..1..1. .0..0..0..1. .0..1..0..0. .0..1..1..1. .0..0..1..1 %e A284225 ..1..1..1..0. .0..0..0..1. .1..1..0..1. .1..1..0..0. .1..0..0..0 %e A284225 ..0..1..0..0. .0..1..0..1. .0..0..1..1. .1..0..1..0. .0..0..0..0 %e A284225 ..1..1..1..0. .0..1..0..1. .1..0..0..1. .1..0..0..0. .1..1..1..1 %Y A284225 Cf. A284222. %K A284225 nonn %O A284225 1,1 %A A284225 _R. H. Hardin_, Mar 23 2017