A080326 Denominator of Sum(k^mu(k): 1<=k<=n), where mu is the Moebius function (A008683).

1, 2, 6, 6, 30, 30, 210, 210, 210, 210, 2310, 2310, 30030, 30030, 30030, 30030, 510510, 510510, 9699690, 9699690, 9699690, 9699690, 223092870, 223092870, 223092870, 223092870, 223092870, 223092870, 6469693230, 3234846615

Offset: 1

Author

Dean Hickerson, Feb 15 2003

Keywords

• nonn
• frac

Comments

a(n) is a divisor of A034386(n), the product of the primes <= n. Does a(n) = A034386(n) for infinitely many n?

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Numerators are in A080306. Cf. A080304, A080305, A034386.

Programs

Mathematica

Accumulate[Table[n^MoebiusMu[n],{n,30}]]//Denominator (* Harvey P. Dale, Jul 28 2021 *)

PARI

a(n) = denominator(sum(k = 1, n, k^moebius(k))); \\ Michel Marcus, Aug 29 2013