|
Search: id:A046692
|
|
| |
|
| 1, -3, -4, 2, -6, 12, -8, 0, 3, 18, -12, -8, -14, 24, 24, 0, -18, -9, -20, -12, 32, 36, -24, 0, 5, 42, 0, -16, -30, -72, -32, 0, 48, 54, 48, 6, -38, 60, 56, 0, -42, -96, -44, -24, -18, 72, -48, 0, 7, -15, 72, -28, -54, 0, 72, 0, 80, 90, -60, 48, -62, 96, -24, 0, 84, -144, -68, -36, 96, -144, -72, 0, -74, 114, -20, -40, 96, -168
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
REFERENCES
|
T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 39.
Feist, Andrew R., Fun With the Sigma-Function, unpub.
|
|
FORMULA
|
a(p) = -p-1, a(p^2) = p, a(p^k) = 0 for k > 2.
|
|
EXAMPLE
|
a(36) = a(2^2*3^2) = 2*3 = 6
|
|
MAPLE
|
t := 1; a := proc(n, t) local t1, d; t1 := 0; for d from 1 to n do if n mod d = 0 then t1 := t1+d^t*mobius(d)*mobius(n/d); fi; od; t1; end;
|
|
PROGRAM
|
(PARI) a(n)=if(n<1, 0, direuler(p=2, n, (1-X)*(1-p*X))[n]) (from R. Stephan)
|
|
CROSSREFS
|
Cf. A000203.
Adjacent sequences: A046689 A046690 A046691 this_sequence A046693 A046694 A046695
Sequence in context: A108127 A049277 A143052 this_sequence A045901 A098003 A026245
|
|
KEYWORD
|
easy,mult,sign,nice
|
|
AUTHOR
|
Andrew R. Feist (arf22540(AT)cmsu2.cmsu.edu)
|
|
EXTENSIONS
|
Corrected by T. D. Noe (noe(AT)sspectra.com), Nov 13 2006
|
|
|
Search completed in 0.002 seconds
|
