A087812 Sum of MoebiusMu for numbers between n and 2n inclusive.

0, -2, -1, -1, 0, 0, -1, 1, 0, -1, 0, 0, 1, 2, -1, -3, -1, 1, 1, 3, 1, -1, -1, -1, -1, 0, -2, -1, 1, 1, 2, 3, 3, 1, 0, -2, -2, -1, -2, -4, -3, -3, 0, 2, 1, 2, 3, 5, 4, 4, 2, 0, 0, 0, -2, -2, -4, -4, -4, -2, -1, 1, 0, -1, -1, -3, 0, 1, -1, -3, 0, 2, 4, 5, 3, 2, 1, 1, 2, 4, 5, 4, 3, 3, 2, 1, -2, -3, -1, -1, -3, -3, -3, -3, -5, -7, -7, -7, -8, -9, -7, -5, -2

Offset

1,2

Links

Table of n, a(n) for n=1..103.

Mathematica

Table[Apply[Plus, Table[MoebiusMu[w], {w, n, 2*n}]], {n, 1, 256}]

Prog

(PARI) a(n) = sum(k=n, 2*n, moebius(k)); \\ Michel Marcus, Nov 15 2025

Crossrefs

Cf. A008683.

Sequence in context: A198066 A141664 A056979 * A288384 A113045 A309365

Adjacent sequences: A087809 A087810 A087811 * A087813 A087814 A087815

Keyword

sign

Author

Labos Elemer, Oct 14 2003

Extensions

Offset set to 1 by Georg Fischer, Nov 15 2025

Status

approved