%I A001232
%S A001232 1089,10989,109989,1099989,10891089,10999989,108901089,109999989,
%T A001232 1089001089,1098910989,1099999989,10890001089,10989010989,10999999989,
%U A001232 108900001089,108910891089,109890010989,109989109989,109999999989
%N A001232 Numbers n such that 9*n = (n written backwards).
%C A001232 Least n-digit number which is a factor of its reversal. Quotient is always 
               9. - Lekraj Beedassy (blekraj(AT)yahoo.com), Jun 11 2004
%C A001232 Fixed points of the map which sends x to x - reverse(x) if that is positive, 
               otherwise to x + reverse(x). - Sebastien DUMORTIER (sdumortier(AT)ac-limoges.fr), 
               Nov 05 2006
%D A001232 H. Camous, Jouer Avec Les maths, "Cardinaux Reversibles", Section I Problem 
               6 pp. 27;37-8 Les Editions D'Organisation Paris 1984.
%D A001232 D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. 
               Penguin Books, NY, 1986, under #1093.
%F A001232 Theorem (David W. Wilson): Terms in this sequence have the form 99*m, 
               where the decimal representation of m contains only 1's and 0's, 
               is palindromic and contains no singleton 1's or 0's. Hence contains 
               Fib([ k/2 ]-1) k-digit elements, k >= 4.
%F A001232 a(n)=11*(10^n -1)=11*A002283(n), for n>1. - Lekraj Beedassy (blekraj(AT)yahoo.com), 
               Jun 11 2004
%e A001232 1089*9=9801.
%Y A001232 Cf. A008918, A008919.
%Y A001232 Sequence in context: A008919 A110843 A023093 this_sequence A039684 A023101 
               A031621
%Y A001232 Adjacent sequences: A001229 A001230 A001231 this_sequence A001233 A001234 
               A001235
%K A001232 base,nonn,nice
%O A001232 1,1
%A A001232 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com)
%E A001232 Corrected and extended by David W. Wilson (davidwwilson(AT)comcast.net) 
               Aug 15 1996, Dec 15 1997.