A324913 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A324913

a(n) = Sum_{k=1..n} 2^k * phi(k), where phi is the Euler totient function A000010.

2, 6, 22, 54, 182, 310, 1078, 2102, 5174, 9270, 29750, 46134, 144438, 242742, 504886, 1029174, 3126326, 4699190, 14136374, 22524982, 47690806, 89633846, 274183222, 408400950, 1079489590, 1884795958, 4300715062, 7521940534, 22554326070, 31144260662, 95568770102

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..31.

Vaclav Kotesovec, Plot of a(n)/(n*2^n) for n = 1..100000

Eric Weisstein's World of Mathematics, Totient Function

Wikipedia, Euler's totient function

MATHEMATICA

Accumulate[Table[2^k*EulerPhi[k], {k, 1, 40}]]

CROSSREFS

Cf. A000010, A002088, A306988.