|
| |
|
|
A078461
|
|
a(n) = 0 if n is divisible by the square of odd prime, a(n) = 1 if n is an odd squarefree number, a(n) = 2 otherwise.
|
|
0
| |
|
|
1, 2, 1, 2, 1, 2, 1, 2, 0, 2, 1, 2, 1, 2, 1, 2, 1, 0, 1, 2, 1, 2, 1, 2, 0, 2, 0, 2, 1, 2, 1, 2, 1, 2, 1, 0, 1, 2, 1, 2, 1, 2, 1, 2, 0, 2, 1, 2, 0, 0, 1, 2, 1, 0, 1, 2, 1, 2, 1, 2, 1, 2, 0, 2, 1, 2, 1, 2, 1, 2, 1, 0, 1, 2, 0, 2, 1, 2, 1, 2, 0, 2, 1, 2, 1, 2, 1, 2, 1, 0, 1, 2, 1, 2, 1, 2, 1, 0, 0, 0, 1, 2, 1, 2, 1
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
FORMULA
| Dirichlet g.f.: zeta(s)/zeta(2s)*2^s/(2^s-1). - Ralf Stephan, Jun 17 2007
|
|
|
PROG
| (PARI) a(n)=if(n<1, 0, direuler(p=2, n, if(p%2==1, 1+X, if(p%2, 1, (1+X)/(1-X))))[n])
|
|
|
CROSSREFS
| Cf. A038838, A056911.
Sequence in context: A062754 A045888 A107279 * A111621 A140195 A196564
Adjacent sequences: A078458 A078459 A078460 * A078462 A078463 A078464
|
|
|
KEYWORD
| mult,nonn
|
|
|
AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Dec 31 2002
|
| |
|
|
