OFFSET
1,2
COMMENTS
phi(n) = A000010(n) = Euler totient function of n.
FORMULA
Logarithmic derivative of A174475.
MATHEMATICA
dph[n_]:=Module[{divs=Divisors[n]}, Total[divs^EulerPhi[divs]]]; Array[ dph, 30] (* Harvey P. Dale, Oct 05 2014 *)
PROG
(PARI) {a(n)=sumdiv(n, d, d^eulerphi(d))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Apr 04 2010
STATUS
approved