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A228640 a(n) = Sum_{d|n} phi(d)*n^(n/d). 4
0, 1, 6, 33, 280, 3145, 46956, 823585, 16781472, 387422001, 10000100440, 285311670721, 8916103479504, 302875106592409, 11112006930972780, 437893890382391745, 18446744078004651136, 827240261886336764449, 39346408075494964903956, 1978419655660313589124321 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..200

MAPLE

with(numtheory):

a:= n-> add(phi(d)*n^(n/d), d=divisors(n)):

seq(a(n), n=0..20);

MATHEMATICA

a[0] = 0; a[n_] := DivisorSum[n, EulerPhi[#]*n^(n/#)&]; Table[a[n], {n, 0, 20}] (* Jean-Fran├žois Alcover, Mar 21 2017 *)

CROSSREFS

Main diagonal of A054618, A054619, A185651.

Cf. A000010.

Sequence in context: A215707 A137970 A024079 * A228618 A118094 A306182

Adjacent sequences:  A228637 A228638 A228639 * A228641 A228642 A228643

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Aug 28 2013

STATUS

approved

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Last modified September 21 07:08 EDT 2019. Contains 327253 sequences. (Running on oeis4.)