login
A073578
a(n) = Sum_{k=1..n} mu(2*k).
1
-1, -1, 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 3, 3, 4, 4, 5, 5, 4, 4, 5, 5, 5, 5, 5, 5, 6, 6, 7, 7, 6, 6, 5, 5, 6, 6, 5, 5, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 7, 7, 8, 8, 7, 7, 6, 6, 7, 7, 8, 8, 8, 8, 7, 7, 8, 8, 7, 7, 8, 8, 9, 9, 9, 9, 8, 8, 9, 9, 9, 9, 10, 10, 9, 9, 8, 8, 9, 9, 8, 8, 7, 7, 6, 6, 7, 7, 7, 7, 8, 8, 9, 9
OFFSET
1,7
COMMENTS
After a(2)=-1, the next negative value is a(8511)=-1.
Observation: It seems that Sum_{k=1..n} a(k) is usually close to n*log(n)*log(log(n)). Is Sum_{k=1..n} a(k) asymptotic to C*n*log(n)*log(log(n)) for some C near 1?
LINKS
MATHEMATICA
Accumulate[MoebiusMu[2Range[110]]] (* Harvey P. Dale, Apr 30 2012 *)
CROSSREFS
Cf. A008683.
Sequence in context: A064658 A194292 A308403 * A087866 A061392 A048273
KEYWORD
easy,sign
AUTHOR
Benoit Cloitre, Aug 28 2002
EXTENSIONS
Edited by Dean Hickerson, Sep 04 2002
STATUS
approved