OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
a = {}; s = 0; Do[s = s + EulerPhi[ Prime[n]]; If[ PrimeQ[s], AppendTo[a, s]], {n, 200}]; a (* Robert G. Wilson v, Dec 22 2004 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jorge Coveiro, Dec 22 2004
EXTENSIONS
Edited and extended by Robert G. Wilson v, Dec 22 2004
STATUS
approved