OFFSET
1,1
COMMENTS
Sequence A221475 contains odd composite numbers with this property.
LINKS
MATHEMATICA
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {}; n = 0; While[Length[t] < 50, n++; p = Prime[n]; If[Union[Drop[PrimeQ[Rest[Collatz[p]]], -2]] == {False}, AppendTo[t, p]]]; t
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Feb 14 2013
STATUS
approved