A157657 a(1) = 1, a(n) = -mu(n) for n >= 2.

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

Offset

1,1

Comments

Apparently the Dirichlet inverse of A114006. [R. J. Mathar, Jul 15 2010]

Not multiplicative; for example a(2)*a(3) != a(6). - R. J. Mathar, Mar 31 2012

Links

Antti Karttunen, Table of n, a(n) for n = 1..5000

Index entries for sequences computed from exponents in factorization of n

Mathematica

a[1]:=1; a[n_]:=-MoebiusMu[n]; Array[a, 100] (* Stefano Spezia, May 03 2025 *)

Prog

(PARI) a(n)=if(n==1, 1, -moebius(n)); \\ Joerg Arndt, Aug 25 2014
(Scheme) (define (A157657 n) (if (= 1 n) 1 (- (A008683 n)))) ;; Antti Karttunen, Jul 26 2017

Crossrefs

Cf. A008683, A157658 (same except for a(1)).

Sequence in context: A008683 A008966 A080323 * A359155 A069158 A353559

Adjacent sequences: A157654 A157655 A157656 * A157658 A157659 A157660

Keyword

sign

Author

Jaroslav Krizek, Mar 03 2009

Extensions

Added more terms, Joerg Arndt, Aug 25 2014

Status

approved