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 A050647 #15 Dec 26 2016 15:07:23
%S A050647 1,11,10011,10000000010011,10000000000000000000000000010000000010011
%N A050647 a(n+1)^3 is next smallest cube ending with a(n)^3, initial term is 1.
%C A050647 _Frank Ellermann_ conjectures (Jun 11 2001) that if b(n) = 10^(3^n -1), i.e., 1, 100, 100000000, etc. then a(n) = concatenation b( n-2 ) || a( n-1 ) for n > 1.
%C A050647 a(6) is too large to include (contains 122 digits).
%F A050647 a(n) = Sum_{i=0..n-1} 10^((3^i-1)/2). - _Max Alekseyev_, Jan 07 2015
%Y A050647 Cf. A050646, A048564, A050641.
%K A050647 nonn,base
%O A050647 1,2
%A A050647 _Patrick De Geest_, Jul 15 1999
%E A050647 More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001, who remarks that a(6) = 10^121+a(5) = concat (10^80, a(5)) and a(7) = 10^364+a(6) = concat (10^242, a(6)), which supports Ellermann's conjecture