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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A034753 Dirichlet convolution of 3^(n-1) with sigma(n). 0

%I #9 Dec 31 2023 15:33:38

%S 1,6,13,43,87,294,737,2304,6610,19962,59061,178111,531455,1596558,

%T 4783371,14355733,43046739,129161004,387420509,1162321341,3486787421,

%U 10460530422,31381059633,94143721320,282429536998,847290203850

%N Dirichlet convolution of 3^(n-1) with sigma(n).

%F a(n) ~ 3^(n-1). - _Vaclav Kotesovec_, Sep 11 2019

%F a(n) = Sum_{d|n} sigma(n/d)*3^(d-1). - _Wesley Ivan Hurt_, Dec 31 2023

%t Table[Sum[DivisorSigma[1, n/d]*3^(d - 1), {d, Divisors[n]}], {n, 1, 25}] (* _Vaclav Kotesovec_, Sep 10 2019 *)

%Y Cf. A000203.

%K nonn

%O 1,2

%A _Erich Friedman_

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 25 01:41 EDT 2024. Contains 374585 sequences. (Running on oeis4.)