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

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..3293

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

Maple

ListTools:-PartialSums([seq(2^k * numtheory:-phi(k), k=1..50)]); # Robert Israel, Apr 17 2025

Mathematica

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

Crossrefs

Cf. A000010, A002088, A306988.

Sequence in context: A246624 A212872 A306967 * A027561 A321626 A126171

Adjacent sequences: A324910 A324911 A324912 * A324914 A324915 A324916

Keyword

nonn

Author

Vaclav Kotesovec, Mar 18 2019

Status

approved