A300547 a(n) = [x^n] Product_{d|n} (1 - x^d).

1, -1, -1, -1, -1, -1, -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, -1, -1, -1, 0, -1, -1, -1, -2, -1, -2, -1, -1, -1, -1, -1, -2, -1, -1, -1, 0, -1, -1, -1, -1, -1, -1, -1, -3, -1, -1, -1, -1, -1, -2, -1, -1, -1, -1, -1, -5, -1, -1, -1, -1, -1, -3, -1, -1, -1, -1, -1, 0, -1, -1, -1, -1, -1, -2, -1, 1, -1, -1, -1, -2, -1

Offset: 0

Author

Ilya Gutkovskiy, Mar 08 2018

Keywords

• sign
• look

Links

• Antti Karttunen, Table of n, a(n) for n = 0..65537
• Index entries for sequences related to partitions

Crossrefs

Cf. A010815, A018818, A033630, A293814, A300548, A300549.

Programs

Mathematica

Table[SeriesCoefficient[Product[(1 - Boole[Mod[n, k] == 0] x^k), {k, 1, n}], {x, 0, n}], {n, 0, 85}]

PARI

A300547(n) = { if(!n,return(1)); my(p=1); fordiv(n,d, p *= (1 - 'x^d)); polcoeff(p,n); }; \\ Antti Karttunen, Sep 25 2018