A346578 a(n) = (1/(4*n)) * Sum_{d|n} mu(n/d) * binomial(4*d,d).

1, 3, 18, 112, 775, 5598, 42287, 328640, 2615085, 21191125, 174303162, 1451424960, 12211799223, 103655906781, 886568152950, 7633233227520, 66105170315083, 575445689879247, 5032380942945321, 44191451767056400, 389514699012969936, 3444925385161998518, 30561576846316109863

Offset: 1

Author

Ilya Gutkovskiy, Jul 24 2021

Keywords

• nonn

Comments

Inverse Euler transform of A002293.

Moebius transform of A261497.

Crossrefs

Cf. A002293, A005810, A008683, A022553, A261497, A346577, A346579, A346580, A346581, A346582.

Programs

Mathematica

Table[(1/(4 n)) Sum[MoebiusMu[n/d] Binomial[4 d, d], {d, Divisors[n]}], {n, 23}]

PARI

a(n) = sumdiv(n, d, moebius(n/d)*binomial(4*d,d))/(4*n); \\ Michel Marcus, Jul 24 2021