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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 Antti Karttunen, Table of n, a(n) for n = 1..10000 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: A324252 A321445 A007423 * A307377 A323882 A084143 Adjacent sequences:  A076541 A076542 A076543 * A076545 A076546 A076547 KEYWORD easy,sign AUTHOR Zak Seidov, Oct 19 2002 STATUS approved

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Last modified March 28 07:59 EDT 2020. Contains 333079 sequences. (Running on oeis4.)