A062963 a(n) = mu(n) * H(n) where H(n) is A023022.

-1, -1, 0, -2, 1, -3, 0, 0, 2, -5, 0, -6, 3, 4, 0, -8, 0, -9, 0, 6, 5, -11, 0, 0, 6, 0, 0, -14, -4, -15, 0, 10, 8, 12, 0, -18, 9, 12, 0, -20, -6, -21, 0, 0, 11, -23, 0, 0, 0, 16, 0, -26, 0, 20, 0, 18, 14, -29, 0, -30, 15, 0, 0, 24, -10, -33, 0, 22, -12, -35, 0, -36, 18, 0, 0, 30, -12, -39, 0, 0, 20, -41, 0, 32, 21, 28, 0, -44, 0, 36, 0, 30, 23, 36

Offset: 2

Author

Jason Earls, Jul 22 2001

Keywords

• easy
• sign

Links

• Paolo Xausa, Table of n, a(n) for n = 2..10000

Crossrefs

Cf. A008683, A023022.

Programs

Mathematica

Join[{-1}, Array[MoebiusMu[#] * EulerPhi[#]/2 &, 100, 3]] (* Paolo Xausa, Apr 17 2024 *)

PARI

a(n) = if(n<=2, -1, eulerphi(n)/2*moebius(n)); \\ Michel Marcus, Apr 14 2024

Formula

a(n) = A008683(n) * A023022(n).