A143729 Sum of termwise product of mu(k) and reduced residue system k mod n

1, 1, -2, -2, -4, -4, -3, -14, -13, -9, 0, -22, -11, -31

Offset

1,3

Links

Table of n, a(n) for n=1..14.

Formula

a(n) = Sum_{1<=k<=n, GCD(k,n)=1} mu(k)*k. Equals row sums of triangle A143728.

Example

a(7) = -3 since the relative primes of 7 (Cf. row 7, triangle A127368) = (1, 2, 3, 4, 5, 6, 0). We apply the termwise product of mu(k), where mu(k) = A008683: (1, -1, -1, 0, -1, 1, -1,...) getting row 7 of triangle A143728: (1, -2, -3, 0, -5, 6, 0), sum = -3.

Crossrefs

Cf. A008683, A143728, A127368

Sequence in context: A169629 A231731 A143358 * A006460 A064137 A329588

Adjacent sequences: A143726 A143727 A143728 * A143730 A143731 A143732

Keyword

sign

Author

Gary W. Adamson, Aug 30 2008

Status

approved