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 A284198 #6 Apr 05 2020 22:40:45 %S A284198 33,1611,105367,14392557,1321614728,178138187113,18564422929880, %T A284198 2429325477564655,271315506003954612,34775052300161919967, %U A284198 4048381878219586826112,512565378120434864463849 %N A284198 Number of n X 7 0..1 arrays with the number of 1's horizontally, antidiagonally or vertically adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero. %C A284198 Column 7 of A284199. %H A284198 R. H. Hardin, <a href="/A284198/b284198.txt">Table of n, a(n) for n = 1..31</a> %e A284198 Some solutions for n=3 %e A284198 ..0..1..0..0..0..0..1. .0..1..1..1..0..0..1. .0..1..0..1..0..1..1 %e A284198 ..1..0..1..1..1..0..1. .1..1..1..0..0..1..1. .1..1..0..0..0..1..1 %e A284198 ..1..0..0..1..0..1..1. .0..0..1..1..0..0..0. .0..0..0..1..1..1..0 %Y A284198 Cf. A284199. %K A284198 nonn %O A284198 1,1 %A A284198 _R. H. Hardin_, Mar 22 2017