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 A138489 #3 Aug 24 2012 10:50:01
%S A138489 5,15,1511,3115,152113,13311215,15411223,1322311415,1541142322,
%T A138489 3213243115,1531331422,2214313315,1531331422,2214313315,1531331422,
%U A138489 2214313315,1531331422,2214313315,1531331422,2214313315,1531331422
%N A138489 Say what you see in previous term, from the right, reporting total number for each digit encountered. Initial term is 5.
%C A138489 After a while sequence has period 2 -> {1531331422,2214313315}
%e A138489 To get the term after 152113, we say: one 3's, three 1's, one 2's, one 5's, so 13311215
%Y A138489 Cf. A063850, A022482, A005150, A005151, A006751, A006715, A006711, A022506-A022513, A138484-A138488, A138490-A138493.
%K A138489 easy,nonn,base
%O A138489 0,1
%A A138489 _Paolo P. Lava_ and _Giorgio Balzarotti_, Mar 20 2008