OFFSET
1,1
COMMENTS
All terms correspond to certified primes (Primo 2.2.0 beta). No more terms through 10000.
a(14) > 10^5. [From Donovan Johnson, Feb 06 2010]
MATHEMATICA
Do[If[PrimeQ[3^n + EulerPhi[n]], Print[n]], {n, 1, 10000}]
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Ryan Propper, Aug 31 2005
EXTENSIONS
a(11)-a(13) from Donovan Johnson, Feb 06 2010
STATUS
approved