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 A050630 #9 Oct 15 2019 00:03:14 %S A050630 4,49,1849,18496,103184964,7383508103184964, %T A050630 544680602158273835081031849649 %N A050630 a(n+1) is next smallest nontrivial square containing a(n) as a substring, initial term is 4. %F A050630 a(n) = A050631(n)^2. %Y A050630 Starting with a(2)=49, the sequence is identical A050632. %Y A050630 Cf. A050631, A048559, A050636. %K A050630 nonn,base,more %O A050630 1,1 %A A050630 _Patrick De Geest_, Jul 15 1999 %E A050630 a(7) from _Max Alekseyev_, Feb 15 2012