OFFSET
0,4
FORMULA
a(n) = -2 if n is an odd prime (A065091).
MATHEMATICA
Table[SeriesCoefficient[Product[1/(1 + Boole[Mod[n, k] == 0] x^k), {k, 1, n}], {x, 0, n}], {n, 0, 85}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Mar 08 2018
STATUS
approved