A080847 a(n) = mu(n)+2, where mu is the Moebius function (A008683).

3, 1, 1, 2, 1, 3, 1, 2, 2, 3, 1, 2, 1, 3, 3, 2, 1, 2, 1, 2, 3, 3, 1, 2, 2, 3, 2, 2, 1, 1, 1, 2, 3, 3, 3, 2, 1, 3, 3, 2, 1, 1, 1, 2, 2, 3, 1, 2, 2, 2, 3, 2, 1, 2, 3, 2, 3, 3, 1, 2, 1, 3, 2, 2, 3, 1, 1, 2, 3, 1, 1, 2, 1, 3, 2, 2, 3, 1, 1, 2, 2, 3, 1, 2, 3, 3, 3, 2, 1, 2, 3, 2, 3, 3, 3, 2, 1, 2, 2, 2, 1, 1, 1, 2, 1

Offset

1,1

Links

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

Index entries for sequences computed from exponents in factorization of n.

Formula

1 <= a(n) <= 3.

Mathematica

MoebiusMu[Range[120]]+2 (* Harvey P. Dale, Dec 31 2021 *)

Prog

(Scheme) (define (A080847 n) (+ 2 (A008683 n))) ;; Antti Karttunen, Jul 26 2017
(PARI) a(n) = moebius(n) + 2; \\ Amiram Eldar, May 17 2025

Crossrefs

Cf. A008683, one more than A007423, one less than A231821.

Cf. A080848, A080849.

Sequence in context: A242248 A107297 A107296 * A326406 A334006 A364683

Adjacent sequences: A080844 A080845 A080846 * A080848 A080849 A080850

Keyword

nonn,easy

Author

Reinhard Zumkeller, Feb 20 2003

Status

approved