OFFSET
1,2
COMMENTS
Sequence A196871 contains these terms and even numbers that are 2^k times terms in this sequence.
LINKS
MATHEMATICA
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {1}; n = 1; While[Length[t] < 50, n = n + 2; If[Union[Drop[PrimeQ[Collatz[n]], -2]] == {False}, AppendTo[t, n]]]; t
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Feb 14 2013
STATUS
approved