|
| |
|
|
A166586
|
|
Totally multiplicative sequence with a(p) = p-2 for prime p.
|
|
17
| |
|
|
1, 0, 1, 0, 3, 0, 5, 0, 1, 0, 9, 0, 11, 0, 3, 0, 15, 0, 17, 0, 5, 0, 21, 0, 9, 0, 1, 0, 27, 0, 29, 0, 9, 0, 15, 0, 35, 0, 11, 0, 39, 0, 41, 0, 3, 0, 45, 0, 25, 0
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,5
|
|
|
FORMULA
| Multiplicative with a(p^e) = (p-2)^e. If n = Product p(k)^e(k) then a(n) = Product (p(k)-2)^e(k). a(2k) = 0 for k >= 1.
a(n)=|Sum(d divides n, phi(n)*mu(n))|, where mu(n) is A008683, and phi(n) is A000010 [From Barbarel Tres Mil (barbarel3000(AT)yahoo.es), Nov 14 2009]
|
|
|
MATHEMATICA
| A166586[n_Integer] := Abs[DivisorSum[n, MoebiusMu[ # ]*EulerPhi[ # ] &]] [From Barbarel Tres Mil (barbarel3000(AT)yahoo.es), Nov 14 2009]
|
|
|
CROSSREFS
| Sequence in context: A136599 A131986 A002656 * A122274 A003966 A123931
Adjacent sequences: A166583 A166584 A166585 * A166587 A166588 A166589
|
|
|
KEYWORD
| nonn,mult
|
|
|
AUTHOR
| Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Oct 17 2009
|
| |
|
|
