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a(n) = Sum_{d|n} d^phi(d).
2

%I #6 Jun 07 2021 22:07:23

%S 1,3,10,19,626,48,117650,4115,531451,10628,25937424602,20800,

%T 23298085122482,7647188,2562891260,4294971411,48661191875666868482,

%U 34543713,104127350297911241532842,25600010644,7355827511504300

%N a(n) = Sum_{d|n} d^phi(d).

%C phi(n) = A000010(n) = Euler totient function of n.

%F Logarithmic derivative of A174475.

%t dph[n_]:=Module[{divs=Divisors[n]},Total[divs^EulerPhi[divs]]]; Array[ dph,30] (* _Harvey P. Dale_, Oct 05 2014 *)

%o (PARI) {a(n)=sumdiv(n,d,d^eulerphi(d))}

%Y Cf. A174475, A000010 (phi).

%Y Cf. A344484.

%K nonn

%O 1,2

%A _Paul D. Hanna_, Apr 04 2010