A331376 Dirichlet convolution of the reduced totient function with itself.

1, 2, 4, 5, 8, 8, 12, 8, 16, 16, 20, 16, 24, 24, 24, 16, 32, 32, 36, 32, 36, 40, 44, 24, 56, 48, 60, 48, 56, 48, 60, 32, 60, 64, 72, 60, 72, 72, 72, 48, 80, 72, 84, 80, 88, 88, 92, 44, 120, 112, 96, 96, 104, 120, 120

Offset: 1

Author

Torlach Rush, Jan 14 2020

Keywords

• nonn

Comments

Differs from A029935 when A002322 differs from A000010.

Crossrefs

Cf. A000010, A029935, A002322.

Programs

PARI

a(n) = sumdiv(n, d, lcm(znstar(d)[2]) * lcm(znstar(n/d)[2]));

Formula

a(n) = Sum{d|n} A002322(d) * A002322(n/d).