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 A050646 #9 Oct 15 2019 11:54:50
%S A050646 1,1331,1003303631331,1000000003003300003006603631003303631331
%N A050646 a(n+1) is next smallest cube ending with a(n), initial term is 1.
%C A050646 a(5) contains 121 digits.
%F A050646 a(n) = A050647(n)^3.
%F A050646 a(n) = (Sum_{i=0..n-1} 10^((3^i-1)/2) )^3. - _Max Alekseyev_, Jan 07 2015
%Y A050646 Cf. A050647, A048563, A050640.
%K A050646 nonn,base
%O A050646 1,2
%A A050646 _Patrick De Geest_, Jul 15 1999