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 A118513 #9 Apr 06 2019 10:42:31
%S A118513 13,32,24,43,35,54,46,65,57,76,68,87,79,98,90,10,2,3,4,5,6,7,8,9,10,2,
%T A118513 3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,
%U A118513 9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10
%N A118513 Define sequence S_m by: initial term = m, reverse digits and add 1 to get next term. Entry shows S_13. This reaches a cycle of length 9 in 15 steps.
%H A118513 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki.
%H A118513 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 1).
%t A118513 Join[{13,32,24,43,35,54,46,65,57,76,68,87,79,98,90},LinearRecurrence[{0,0,0,0,0,0,0,0,1},{10,2,3,4,5,6,7,8,9},73]] (* _Ray Chandler_, Jul 18 2015 *)
%t A118513 NestList[IntegerReverse[#]+1&,13,90] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 06 2019 *)
%Y A118513 Cf. A118510, A117831, A117230, A118512.
%K A118513 nonn,base
%O A118513 1,1
%A A118513 _N. J. A. Sloane_, May 06 2006