A297382 Denominator of -A023900(n)/2.

2, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset: 1

Author

Mats Granvik, Dec 29 2017

Keywords

• nonn
• frac

Comments

Also denominator of A173557(n)/2. a(n) = 2 iff n is a power of 2, 1 otherwise. - Antti Karttunen, Sep 30 2018

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537

Crossrefs

Cf. A297381 (numerators).

Cf. A023900, A173557, A014963.

One more than A209229.

Programs

Mathematica

Clear[n, s, nn]; nn = 64; Denominator[Table[Limit[Zeta[s]*Total[MoebiusMu[Divisors[n]]/Divisors[n]^(s - 1)], s -> 0], {n, 1, nn}]]

PARI

A297382(n) = denominator(-(1/2)*factorback(apply(p -> 1-p, factor(n)[, 1]))); \\ Antti Karttunen, Sep 30 2018

Formula

a(n) = denominator of -A023900(n)/2.

a(n) = 1 + A209229(n). - Antti Karttunen, Sep 30 2018

a(n) = A014963(2*n). - Ridouane Oudra, Jul 03 2025

Extensions

More terms from Antti Karttunen, Sep 30 2018