A323913 Sum of A083254 (2*phi(n) - n) and its Dirichlet inverse.

2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 6, 0, 0, -4, 0, 0, 10, 0, 0, 0, 9, 0, 5, 0, 0, -16, 0, 0, 18, 0, 30, -4, 0, 0, 22, 0, 0, -24, 0, 0, 11, 0, 0, 0, 25, -12, 30, 0, 0, -18, 54, 0, 34, 0, 0, -24, 0, 0, 21, 0, 66, -40, 0, 0, 42, -32, 0, 0, 0, 0, 9, 0, 90, -48, 0, 0, 19, 0, 0, -40, 90, 0, 54, 0, 0, -38, 110, 0, 58, 0, 102, 0, 0, -20

Offset: 1

Author

Antti Karttunen, Feb 12 2019

Keywords

• sign

Links

• Antti Karttunen, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A000010, A083254, A319340, A323911, A323912.

Programs

PARI

up_to = 16384;
DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(dA083254(n) = (2*eulerphi(n)-n);
v323912 = DirInverse(vector(up_to,n,A083254(n)));
A323912(n) = v323912[n];
A323913(n) = (A083254(n)+A323912(n));