%I #6 Jan 02 2013 22:05:12

%S 1,2,8,13,12,99,154,153,77,98,97,264,210,235,234,114,113,218,159,158,

%T 157,350,393,392,329,328,327,311,310,309,308,307,270,455,454,435,434,

%U 632,607,606,605,604,603,602,591,573,572,644,643,779,723,717,716,813

%N Length of the Collatz iteration (3x+1) starting at A220139(n).

%H T. D. Noe, <a href="/A220140/b220140.txt">Table of n, a(n) for n = 1..10000</a>

%t Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; c = {1}; t = {}; Do[AppendTo[t, Length[c]]; c = Collatz[Max[c] + 1], {100}]; t

%K nonn

%O 1,2

%A _T. D. Noe_, Jan 02 2013