login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A054611 a(n) = Sum_{d|n} phi(d)*4^(n/d). 4
0, 4, 20, 72, 280, 1040, 4200, 16408, 65840, 262296, 1049680, 4194344, 16782000, 67108912, 268451960, 1073744160, 4295033440, 17179869248, 68719747320, 274877907016, 1099512679520, 4398046544304, 17592190238920, 70368744177752 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..1660

T. Pisanski, D. Schattschneider and B. Servatius, Applying Burnside's lemma to a one-dimensional Escher problem, Math. Mag., 79 (2006), 167-180. See V(n).

FORMULA

a(n) = n * A001868(n).

MAPLE

A054611:=proc(n) local k, t1; t1:=0; for k in divisors(n) do t1 := t1+phi(k)*4^(n/k); od: t1; end;

PROG

(PARI) a(n) = if(n==0, 0, sumdiv(n, d, eulerphi(d)*4^(n/d))); \\ Michel Marcus, Sep 19 2017

CROSSREFS

Column k=4 of A185651.

Sequence in context: A303011 A197426 A061981 * A196432 A302815 A196508

Adjacent sequences:  A054608 A054609 A054610 * A054612 A054613 A054614

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Apr 16 2000

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 21 19:27 EDT 2019. Contains 328312 sequences. (Running on oeis4.)