%I #5 Oct 15 2013 22:32:34
%S 0,1,2,4,6,10,18,30,42,78,114,186,294,390,582,798,1194,1950,2922,4074,
%T 5586,7770,11154,15810,22110,30702,42570,53130,68970,105090,159390,
%U 206910,278850,361410,462210,688722,1019202,1389810,2053770,3011850
%N Smallest number m such that the trajectory of m under iteration of cototient function[=A051953] contains exactly n distinct numbers (including m and the fixed point=0). Or: the required number of iterations[=operations,transitions] is n-1.
%C Analogous to A007755. Separating prime and composite least numbers is not more informative [contrary to totient-iterations] because trajectory-length=3 for all primes and except 2, all terms here are composite numbers.
%e Trajectories for lengths=n=1,2,3,4 are: {0},{1,0},{2,1,0},{4,2,1,0}
%e n=15:{390,294,210,162,108,72,48,32,16,8,4,2,1,0}
%Y Cf. A051953, A000010, A007755, A098196.
%K nonn
%O 1,3
%A _Labos Elemer_, Sep 16 2004