A345049 a(n) = A173557(n) * A345001(n).

-1, 0, -2, 3, -12, 10, -30, 11, 2, 20, -90, 40, -132, 30, 16, 31, -240, 48, -306, 104, 0, 50, -462, 112, -36, 60, 26, 192, -756, 344, -870, 79, -80, 80, -240, 158, -1260, 90, -144, 312, -1560, 636, -1722, 440, 216, 110, -2070, 280, -162, 152, -320, 600, -2652, 186, -880, 600, -432, 140, -3306, 1120, -3540, 150, 348, 191

Offset: 1

Author

Antti Karttunen, Jun 06 2021

Keywords

• sign

Crossrefs

Cf. A173557, A345001, A345048, A345050, A345051.

Programs

PARI

A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A173557(n) = factorback(apply(p -> p-1,factor(n)[,1]));
A345001(n) = (sigma(n)+A003415(n)-(2*n));
A345049(n) = (A173557(n) * A345001(n));

Formula

a(n) = A173557(n) * A345001(n).

a(n) = A345048(n) - A345050(n).