OFFSET
1,2
COMMENTS
Numbers k such that p=6k+1 is prime and the greatest prime divisor of p-1 is 3.
MATHEMATICA
Do[If[Take[FactorInteger[EulerPhi[6n+1]][[ -1]], 1]=={3} && PrimeQ[6n+1], Print[n]], {n, 1, 100000}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 13 2006
EXTENSIONS
Edited by Don Reble, Apr 24 2007
STATUS
approved