|
| |
|
|
A085906
|
|
Ramanujan sum c_n(6).
|
|
3
| |
|
|
1, 1, 2, -2, -1, 2, -1, 0, -3, -1, -1, -4, -1, -1, -2, 0, -1, -3, -1, 2, -2, -1, -1, 0, 0, -1, 0, 2, -1, -2, -1, 0, -2, -1, 1, 6, -1, -1, -2, 0, -1, -2, -1, 2, 3, -1, -1, 0, 0, 0, -2, 2, -1, 0, 1, 0, -2, -1, -1, 4, -1, -1, 3, 0, 1, -2, -1, 2, -2, 1, -1, 0, -1, -1, 0, 2, 1, -2, -1, 0, 0, -1, -1, 4, 1, -1, -2, 0, -1, 3, 1, 2, -2, -1, 1, 0, -1, 0, 3, 0
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
REFERENCES
| T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976.
|
|
|
LINKS
| Wikipedia, Ramanujan's sum
|
|
|
FORMULA
| a(n) = phi(n)*mu(n/gcd(n, 6)) / phi(n/gcd(n, 6)).
Dirichlet g.f. (1+2^(1-s)+3^(1-s)+6^(1-s))/zeta(s). - R. J. Mathar, Mar 26 2011
|
|
|
PROG
| (PARI) a(n)=eulerphi(n)*moebius(n/gcd(n, 6))/eulerphi(n/gcd(n, 6))
|
|
|
CROSSREFS
| Cf. A085639, A085384, A085097.
Sequence in context: A130071 A038540 A084348 * A090406 A152723 A137454
Adjacent sequences: A085903 A085904 A085905 * A085907 A085908 A085909
|
|
|
KEYWORD
| sign,mult
|
|
|
AUTHOR
| Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 16 2003
|
|
|
EXTENSIONS
| More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 18 2003
|
| |
|
|
