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 A138493 #3 Aug 24 2012 10:50:01
%S A138493 9,19,1911,3119,192113,13311219,19411223,1322311419,1941142322,
%T A138493 3213243119,1931331422,2214313319,1931331422,2214313319,1931331422,
%U A138493 2214313319,1931331422,2214313319,1931331422,2214313319,1931331422
%N A138493 Say what you see in previous term, from the right, reporting total number for each digit encountered. Initial term is 9.
%C A138493 After a while sequence has period 2 -> {1931331422,2214313319}
%e A138493 To get the term after 192113, we say: one 3's, three 1's, one 2's, one 9's, so 13311219
%Y A138493 Cf. A063850, A022482, A005150, A005151, A006751, A006715, A006711, A022506-A022513, A138484-A138492.
%K A138493 easy,nonn,base
%O A138493 0,1
%A A138493 _Paolo P. Lava_ and _Giorgio Balzarotti_, Mar 20 2008