OFFSET
1,1
EXAMPLE
phi(101)+sigma(101)=202=2*101.
MATHEMATICA
Select[Range[200], PrimeOmega[EulerPhi[#]+DivisorSigma[1, #]]==2&] (* Harvey P. Dale, Feb 05 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved