A346579 a(n) = (1/(5*n)) * Sum_{d|n} mu(n/d) * binomial(5*d,d).

1, 4, 30, 240, 2125, 19776, 192129, 1922496, 19692504, 205444500, 2175519379, 23322637440, 252631900235, 2760767859780, 30400169155500, 336977763170048, 3757141504436392, 42107201575798248, 474084628585822412, 5359833703935374000, 60823006052351537106, 692556314455384443196

Offset: 1

Author

Ilya Gutkovskiy, Jul 24 2021

Keywords

• nonn

Comments

Inverse Euler transform of A002294.

Moebius transform of A261498.

Crossrefs

Cf. A001449, A002294, A008683, A022553, A261498, A346577, A346578, A346580, A346581, A346582.

Programs

Mathematica

Table[(1/(5 n)) Sum[MoebiusMu[n/d] Binomial[5 d, d], {d, Divisors[n]}], {n, 22}]

PARI

a(n) = sumdiv(n, d, moebius(n/d)*binomial(5*d,d))/(5*n); \\ Michel Marcus, Jul 24 2021