OFFSET
1,1
COMMENTS
LINKS
Harold Shapiro, An arithmetic function arising from the phi function, Amer. Math. Monthly, Vol. 50, No. 1 (1943), 18-30.
MATHEMATICA
nn=20; pk=Table[0, {nn}]; Do[p=Prime[n]; k=Length[NestWhileList[EulerPhi, p, #>2&]]-1; If[0<k<=nn, pk[[k]]=p], {n, PrimePi[1+2*3^(nn-1)]}]; pk
CROSSREFS
KEYWORD
nonn,more
AUTHOR
T. D. Noe, Dec 12 2007
STATUS
approved