A174476 a(n) = Sum_{d|n} d^phi(d).

1, 3, 10, 19, 626, 48, 117650, 4115, 531451, 10628, 25937424602, 20800, 23298085122482, 7647188, 2562891260, 4294971411, 48661191875666868482, 34543713, 104127350297911241532842, 25600010644, 7355827511504300

Offset

1,2

Comments

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

Links

Table of n, a(n) for n=1..21.

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

Cf. A174475, A000010 (phi).

Cf. A344484.

Sequence in context: A027177 A048343 A056789 * A098645 A089693 A194116

Adjacent sequences: A174473 A174474 A174475 * A174477 A174478 A174479

Keyword

nonn

Author

Paul D. Hanna, Apr 04 2010

Status

approved