%I A033619
%S A033619 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,
               27,28,29,30,31,32,33,34,35,36,37,38,39,
%T A033619 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,
               63,64,65,66,67,68,69,70,71,72,73,74,75,76,
%U A033619 77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,
               101,111,121,131,141,151
%N A033619 Undulating numbers (of form abababab... in base 10).
%D A033619 C. A. Pickover, "Keys to Infinity", Wiley 1995, p. 159,160.
%D A033619 C. A. Pickover, "Wonders of Numbers", Oxford New York 2001, Chapter 52, 
               pp. 123-124, 316-317.
%H A033619 C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind 
               and Meaning," <a href="http://www.emis.de/cgi-bin/zmen/ZMATH/en/quick.html?first=1&maxdocs=3&type=html&an\
               =0983.00008&format=complete">Zentralblatt review</a>
%H A033619 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               UndulatingNumber.html">Link to a section of The World of Mathematics.</
               a>
%Y A033619 Sequence in context: A000027 A001477 A087156 this_sequence A130734 A090108 
               A090109
%Y A033619 Adjacent sequences: A033616 A033617 A033618 this_sequence A033620 A033621 
               A033622
%K A033619 nonn,base,easy
%O A033619 0,3
%A A033619 N. J. A. Sloane (njas(AT)research.att.com).