A344863 a(n) = mu(sigma(n)).

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

Offset

1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sigma(n).

Formula

a(n) = A008683(A000203(n)).

Example

a(8) = mu(sigma(8)) = mu(1+2+4+8) = mu(15) = 1.

Mathematica

Table[MoebiusMu[DivisorSigma[1, n]], {n, 100}]

Prog

(PARI) a(n) = moebius(sigma(n)); \\ Amiram Eldar, May 28 2025

Crossrefs

Cf. A008683 (mu), A000203 (sigma).

Sequence in context: A123594 A286801 A189091 * A145006 A189138 A213719

Adjacent sequences: A344860 A344861 A344862 * A344864 A344865 A344866

Keyword

sign,easy

Author

Wesley Ivan Hurt, May 31 2021

Status

approved