OFFSET
2,2
COMMENTS
If the starting n is itself a prime, it counts as a step but the iteration continues despite its prime status (see the example). [From Harvey P. Dale, Nov 11 2011]
EXAMPLE
3-->4-->6-->9-->13. Hence 4 steps are needed and a(3)=4.
MATHEMATICA
Table[Length[NestWhileList[Floor[(3 #)/2]&, Floor[(3n)/2], !PrimeQ[#]&]], {n, 2, 100}] (* Harvey P. Dale, Nov 11 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Mar 08 2003
STATUS
approved