OFFSET
1,1
COMMENTS
Primes in A109606.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Table[EulerPhi[n]-1, {n, 1, 1000}], PrimeQ]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jul 13 2012
STATUS
approved