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

1,2

Comments

Differs from A029935 when A002322 differs from A000010.

Links

Table of n, a(n) for n=1..55.

Formula

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

Prog

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

Crossrefs

Cf. A000010, A029935, A002322.

Sequence in context: A036699 A036694 A085624 * A369601 A345426 A061884

Adjacent sequences: A331373 A331374 A331375 * A331377 A331378 A331379

Keyword

nonn

Author

Torlach Rush, Jan 14 2020

Status

approved