%I A033665
%S A033665 0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1,2,1,1,0,1,1,1,1,1,2,1,1,1,1,0,1,
%T A033665 1,1,2,1,2,1,1,1,1,0,1,2,1,2,2,1,1,1,1,1,0,1,2,2,3,1,1,1,1,2,1,0,2,3,4,
%U A033665 1,1,1,2,1,2,2,0,4,6,1,1,2,1,2,2,3,4,0,24,1,2,1,2,2,3,4,6,24,0,1,0,1,1
%N A033665 Number of 'Reverse and Add' steps needed to reach a palindrome, or -1 
               if never reaches a palindrome.
%C A033665 Palindromes themselves are not 'Reverse and Add!'ed, so they yield a 
               zero !
%D A033665 D. Wells, The Penguin Dictionary of Curious and Interesting Numbers, 
               pp. 142-3 Penguin Books 1987.
%H A033665 P. De Geest, <a href="http://www.worldofnumbers.com/weblinks.htm">Some 
               thematic websources</a>
%H A033665 Jason Doucette, <a href="http://www.jasondoucette.com/worldrecords.html#Most">
               World Records</a>
%H A033665 S. K. Eddins, <a href="http://staff.imsa.edu/math/journal/volume4/articles/
               Palindrome.pdf">The Palindromic Order Of A Number</a>
%H A033665 I. Peter, <a href="http://www.floot.demon.co.uk/palindromes.html">More 
               trajectories</a>
%H A033665 T. Trotter, Jr., <a href="http://www.trottermath.net/numthry/palndrom.html">
               Palindrome Power</a>
%H A033665 <a href="Sindx_Res.html#RAA">Index entries for sequences related to Reverse 
               and Add!</a>
%e A033665 19 -> 19+91=110 -> 110+011 = 110+11 = 121 = palindrome, took 2 steps, 
               so a(19)=2.
%Y A033665 Cf. A023109, A006960, A016016, A023109, A006960.
%Y A033665 Sequence in context: A005090 A073490 A135341 this_sequence A104234 A037870 
               A026920
%Y A033665 Adjacent sequences: A033662 A033663 A033664 this_sequence A033666 A033667 
               A033668
%K A033665 nonn,base,easy
%O A033665 0,20
%A A033665 N. J. A. Sloane (njas(AT)research.att.com).
%E A033665 More terms from Patrick De Geest (pdg(AT)worldofnumbers.com), Jun 15 
               1998.