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A076544 mu(n)+sqf(n): mu(n) is Moebius function; sqf(n)=1 if n is squarefree, sqf(n)=-1 otherwise. 1
2, 0, 0, -1, 0, 2, 0, -1, -1, 2, 0, -1, 0, 2, 2, -1, 0, -1, 0, -1, 2, 2, 0, -1, -1, 2, -1, -1, 0, 0, 0, -1, 2, 2, 2, -1, 0, 2, 2, -1, 0, 0, 0, -1, -1, 2, 0, -1, -1, -1, 2, -1, 0, -1, 2, -1, 2, 2, 0, -1, 0, 2, -1, -1, 2, 0, 0, -1, 2, 0, 0, -1, 0, 2, -1, -1, 2, 0, 0, -1, -1, 2, 0, -1, 2, 2, 2, -1, 0, -1, 2, -1, 2, 2, 2, -1, 0, -1, -1, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = mu(n) + -1^(1+abs(mu(n))), where mu(n) = A008683(n). - Antti Karttunen, Jul 26 2017
MATHEMATICA
ms[n_]:=MoebiusMu[n]+If[SquareFreeQ[n], 1, -1]; Array[ms, 100] (* Harvey P. Dale, Feb 22 2013 *)
PROG
(Scheme) (define (A076544 n) (+ (A008683 n) (expt -1 (+ 1 (abs (A008683 n)))))) ;; Antti Karttunen, Jul 26 2017
CROSSREFS
Absolute values give A007423.
Cf. A008683.
Sequence in context: A321445 A353459 A007423 * A349912 A345079 A307377
KEYWORD
easy,sign
AUTHOR
Zak Seidov, Oct 19 2002
STATUS
approved

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Last modified March 29 09:14 EDT 2024. Contains 371268 sequences. (Running on oeis4.)