A099991 - OEIS

%I #24 Aug 12 2021 05:04:00

%S -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,

%T -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,

%U 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

%N a(n) = Moebius(2n).

%C 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

%H Antti Karttunen, <a href="/A099991/b099991.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A008683(2n). - _Wesley Ivan Hurt_, Dec 17 2013

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

%t MoebiusMu[2*Range[110]] (* _Harvey P. Dale_, Jul 13 2012 *)

%o (PARI) A099991(n) = moebius(2*n); \\ _Antti Karttunen_, Sep 14 2017

%Y Bisection of A008683. Cf. A099990.

%K sign,easy

%O 1,1

%A _N. J. A. Sloane_, Nov 20 2004