%I #3 Mar 30 2012 16:47:44
%S 3,40,20,10,5,66,33,430,215,2796,1398,699,9088,4544,2272,1136,568,284,
%T 142,71,924,462,231,3004,1502,751,9764,4882,2441,31734,15867,206272,
%U 103136,51568,25784,12892,6446
%N Trajectory of 3 under map n->13n+1 if n odd, n->n/2 if n even
%K nonn
%O 0,1
%A _N. J. A. Sloane_.