A062562 a(n) = Sum_{k=1..n} mu(k)*sigma(k).

0, 1, -2, -6, -6, -12, 0, -8, -8, -8, 10, -2, -2, -16, 8, 32, 32, 14, 14, -6, -6, 26, 62, 38, 38, 38, 80, 80, 80, 50, -22, -54, -54, -6, 48, 96, 96, 58, 118, 174, 174, 132, 36, -8, -8, -8, 64, 16, 16, 16, 16, 88, 88, 34, 34, 106, 106, 186, 276, 216, 216, 154, 250, 250, 250, 334, 190, 122, 122, 218, 74, 2, 2, -72, 42, 42, 42

Offset: 0

Author

Jason Earls, Jul 03 2001

Keywords

• sign

Crossrefs

Partial sums of A063441.

Programs

Mathematica

Table[Sum[MoebiusMu[k]DivisorSigma[1,k],{k,n}],{n,0,80}] (* Harvey P. Dale, Nov 08 2011 *)

PARI

s=[]; for(n=0,130,s=concat(s,sum(k=1,n,moebius(k)*sigma(k)))); s

Extensions

Corrected by Harvey P. Dale, Nov 08 2011