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 A284228 #6 Apr 05 2020 22:50:39 %S A284228 64,2719,170155,19371893,2058141264,232036495984,26772321109067, %T A284228 3148948157013672,375099683101859897,45101225320947864321, %U A284228 5461569534638135452419,665104722603120565892383 %N A284228 Number of 7 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 A284228 Row 7 of A284222. %H A284228 R. H. Hardin, <a href="/A284228/b284228.txt">Table of n, a(n) for n = 1..24</a> %e A284228 Some solutions for n=3 %e A284228 ..0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0 %e A284228 ..1..1..0. .1..1..0. .0..1..0. .0..1..1. .1..0..0. .0..0..1. .1..0..1 %e A284228 ..0..1..1. .1..1..1. .0..1..0. .1..1..1. .1..0..1. .1..0..0. .1..0..0 %e A284228 ..1..1..1. .0..0..0. .1..0..1. .1..1..0. .1..1..0. .1..1..1. .1..0..1 %e A284228 ..0..1..0. .1..1..1. .1..0..1. .0..0..1. .1..0..0. .1..0..1. .0..1..1 %e A284228 ..1..0..1. .1..1..0. .1..1..1. .1..0..1. .0..1..1. .0..0..1. .0..0..0 %e A284228 ..0..0..1. .1..0..0. .0..1..0. .1..1..0. .1..1..0. .0..1..0. .1..1..0 %Y A284228 Cf. A284222. %K A284228 nonn %O A284228 1,1 %A A284228 _R. H. Hardin_, Mar 23 2017