OFFSET
1,1
COMMENTS
LINKS
MATHEMATICA
Position[#, k_ /; k > 0][[All, 1]] &@ Table[Length@ NestWhileList[If[OddQ@ #, 3 # + 1, #/2] &, n, # > 1 &] - Length@ NestWhileList[Flatten[# /. {k_ /; OddQ@ k :> 3 k + 1, k_ /; EvenQ@ k :> {k/2, 3 k + 1}}] &, {n}, FreeQ[#, 1] &], {n, 126}] (* Michael De Vlieger, Aug 20 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
David Applegate and N. J. A. Sloane, Feb 04 2007
EXTENSIONS
More terms from Antti Karttunen, Aug 18 2017
STATUS
approved