%I A064685
%S A064685 1,8,6,17,20,15,10,18,13,21,8,16,24,112,19,107,27,14,22,35,110,30,17,
%T A064685 105,25,25,12,113,33,33,20,108,28,28,15,103,116,15,23,36,23,111,10,31,
%U A064685 31,93,18,106,119,26,26,88,39,101,114,70,13,34,21,34,96,47,109,47,122
%N A064685 Length of orbit of 2n+1 in the 3x+1 problem.
%H A064685 <a href="Sindx_3.html#3x1">Index entries for sequences related to 3x+1 
               (or Collatz) problem</a>
%F A064685 f(n)= n/2 if n is even, 3n+1 if n is odd; stop if n is 1.
%e A064685 E.g. orbit(3) = 3->10->5->16->8->4->2->1, so length of chain = 8
%o A064685 (ARIBAS): function a064685(maxarg: integer); var n: integer; begin for 
               n := 1 to maxarg by 2 do write(length(orbit(n))," "); end; end; a064685(140). 
               For definition of function orbit see A064684.
%Y A064685 Sequence in context: A034085 A119876 A036176 this_sequence A075486 A123875 
               A058088
%Y A064685 Adjacent sequences: A064682 A064683 A064684 this_sequence A064686 A064687 
               A064688
%K A064685 nonn,easy
%O A064685 0,2
%A A064685 Jon Perry (perry(AT)globalnet.co.uk), Oct 10 2001
%E A064685 More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Oct 
               13 2001