A198591 Odd numbers producing 8 odd numbers in the Collatz iteration.

25, 49, 51, 99, 101, 197, 205, 217, 397, 405, 433, 435, 441, 475, 789, 821, 833, 857, 867, 869, 875, 883, 951, 953, 955, 1589, 1621, 1649, 1667, 1713, 1715, 1733, 1741, 1751, 1765, 1785, 1901, 1907, 1911, 3157, 3185, 3285, 3299, 3333, 3427, 3429, 3469, 3477

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1938

Mathematica

Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {}; Do[If[Length[Select[Collatz[n], OddQ]] == 8, AppendTo[t, n]], {n, 1, 10000, 2}]; t

Crossrefs

Cf. A198584.

Sequence in context: A004936 A062058 A273510 * A069063 A064937 A245272

Adjacent sequences: A198588 A198589 A198590 * A198592 A198593 A198594

Keyword

nonn

Author

T. D. Noe, Oct 31 2011

Status

approved