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

Author

Reinhard Zumkeller, Feb 20 2003

Keywords

• nonn
• easy

Links

• Antti Karttunen, Table of n, a(n) for n = 1..5000
• Index entries for sequences computed from exponents in factorization of n.

Crossrefs

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

Cf. A080848, A080849.

Programs

Mathematica

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

PARI

a(n) = moebius(n) + 2; \\ Amiram Eldar, May 17 2025

Scheme

(define (A080847 n) (+ 2 (A008683 n))) ;; Antti Karttunen, Jul 26 2017

Formula

1 <= a(n) <= 3.