A198593 - OEIS

%I #6 Mar 30 2012 17:23:03

%S 43,87,89,173,177,179,349,355,357,385,423,693,705,709,717,729,761,769,

%T 771,777,847,1393,1397,1411,1415,1421,1429,1457,1459,1465,1481,1523,

%U 1539,1541,1547,1555,1569,1689,1693,1697,2773,2787,2801,2821,2831,2837,2869

%N Odd numbers producing 10 odd numbers in the Collatz iteration.

%H T. D. Noe, <a href="/A198593/b198593.txt">Table of n, a(n) for n = 1..1000</a>

%t Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {}; Do[If[Length[Select[Collatz[n], OddQ]] == 10, AppendTo[t, n]], {n, 1, 10000, 2}]; t

%Y Cf. A198584.

%K nonn

%O 1,1

%A _T. D. Noe_, Oct 31 2011