A099991 a(n) = Moebius(2n).

-1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, -1, 0, 1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, -1, 0, -1, 0, 1, 0, -1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 1, 0, -1, 0, -1, 0, 1, 0, 1, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, 1, 0, 0, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, -1, 0, 1, 0, -1, 0, -1, 0, -1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1

Offset: 1

Author

N. J. A. Sloane, Nov 20 2004

Keywords

• sign
• easy

Comments

b(n) = -a(n) is multiplicative with b(2^e) = 0, b(p) = -1 if p >= 3, 0 otherwise. - David W. Wilson, Jun 12 2005

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Bisection of A008683. Cf. A099990.

Programs

Maple

with(numtheory); A099991:=n->mobius(2*n); seq(A099991(n), n=1..100); # Wesley Ivan Hurt, Dec 17 2013

Mathematica

MoebiusMu[2*Range[110]] (* Harvey P. Dale, Jul 13 2012 *)

PARI

A099991(n) = moebius(2*n); \\ Antti Karttunen, Sep 14 2017

Formula

a(n) = A008683(2n). - Wesley Ivan Hurt, Dec 17 2013