1,7

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?

Table of n, a(n) for n=1..104.

Accumulate[MoebiusMu[2Range[110]]] (* Harvey P. Dale, Apr 30 2012 *)

Sequence in context: A064658 A194292 A308403 * A087866 A061392 A048273

Adjacent sequences: A073575 A073576 A073577 * A073579 A073580 A073581

easy,sign

Benoit Cloitre, Aug 28 2002

Edited by Dean Hickerson, Sep 04 2002

approved