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