OFFSET
0,5
EXAMPLE
O.g.f.: 1/((1 - x)(1 + x^2)(1 - x^3)(1 - x^5)(1 + x^6)(1 - x^7)(1 + x^10)...).
MATHEMATICA
nn=20;
radQ[n_]:=Or[n==1, GCD@@FactorInteger[n][[All, 2]]==1];
ser=Product[1/(1+(-x)^p), {p, Select[Range[nn], radQ]}];
Table[SeriesCoefficient[ser, {x, 0, n}], {n, 0, nn}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jun 07 2018
STATUS
approved