%I A139391
%S A139391 1,1,5,1,1,3,11,1,7,5,17,3,5,7,23,1,13,9,29,5,1,11,35,3,19,13,41,7,11,
%T A139391 15,47,1,25,17,53,9,7,19,59,5,31,21,65,11,17,23,71,3,37,25,77,13,5,27,
%U A139391 83,7,43,29,89,15,23,31,95,1,49,33,101,17,13,35,107,9,55,37,113,19,29
%N A139391 Next odd term in Collatz trajectory with starting value n.
%C A139391 a(n) = A006370(n) iff n mod 4 = 2;
%C A139391 a(A016825(n))=A006370(A016825(n));
%C A139391 a(n) = A000265(A006370(n)).
%C A139391 a(A160967(n)) = 1. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               May 31 2009]
%D A139391 Friedrich L. Bauer, 'Der (ungerade) Collatz-Baum', Informatik Spektrum 
               31 (Springer, April 2008).
%H A139391 R. Zumkeller, <a href="b139391.txt">Table of n, a(n) for n = 1..10000</
               a>
%H A139391 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               CollatzProblem.html">Collatz Problem</a>
%H A139391 <a href="Sindx_3.html#3x1">Index entries for sequences related to 3x+1 
               (or Collatz) problem</a>
%H A139391 Wikipedia, <a href="http://en.wikipedia.org/wiki/Collatz_conjecture">
               Collatz conjecture</a> [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               May 31 2009]
%F A139391 a(n) = if A006370(n) is odd then A006370(n) else a(A006370(n)).
%Y A139391 Sequence in context: A073050 A154740 A154567 this_sequence A110635 A071170 
               A108691
%Y A139391 Adjacent sequences: A139388 A139389 A139390 this_sequence A139392 A139393 
               A139394
%K A139391 nonn
%O A139391 1,3
%A A139391 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 17 2008