A373926 a(n) = Sum_{d|n} (-1)^phi(d) * mu(n/d).

-1, 0, 2, 2, 2, 0, 2, 0, 0, 0, 2, -2, 2, 0, -2, 0, 2, 0, 2, -2, -2, 0, 2, 0, 0, 0, 0, -2, 2, 0, 2, 0, -2, 0, -2, 0, 2, 0, -2, 0, 2, 0, 2, -2, 0, 0, 2, 0, 0, 0, -2, -2, 2, 0, -2, 0, -2, 0, 2, 2, 2, 0, 0, 0, -2, 0, 2, -2, -2, 0, 2, 0, 2, 0, 0, -2, -2, 0, 2, 0, 0, 0, 2, 2, -2, 0, -2, 0, 2

Offset

1,3

Comments

Möbius transform of (-1)^phi(n) (which equals -1 if 1 <= n <= 2, and 1 if n >= 3).

Links

Table of n, a(n) for n=1..89.

Mathematica

Table[DivisorSum[n, (-1)^EulerPhi[#] MoebiusMu[n/#] &], {n, 100}]

Crossrefs

Cf. A000010 (phi), A008683 (mu), A373925.

Sequence in context: A171958 A301735 A133625 * A176154 A274718 A028930

Adjacent sequences: A373923 A373924 A373925 * A373927 A373928 A373929

Keyword

sign

Author

Wesley Ivan Hurt, Jun 22 2024

Status

approved