A198593 Odd numbers producing 10 odd numbers in the Collatz iteration.

43, 87, 89, 173, 177, 179, 349, 355, 357, 385, 423, 693, 705, 709, 717, 729, 761, 769, 771, 777, 847, 1393, 1397, 1411, 1415, 1421, 1429, 1457, 1459, 1465, 1481, 1523, 1539, 1541, 1547, 1555, 1569, 1689, 1693, 1697, 2773, 2787, 2801, 2821, 2831, 2837, 2869

Offset: 1

Author

T. D. Noe, Oct 31 2011

Keywords

• nonn

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A198584.

Programs

Mathematica

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