/* polylogarithm by dark-beam */
// approx (very good) of Li[n](z) for n > 1
double vv = pAmount;
Complex z = new Complex(pAffineTP.x, pAffineTP.y);
z.Pow(zpow);
z.Save();
if (z.Mag2() > 250000.0 || N >= 20) { // no convergence, or N too big... When N is big then Li tends to z
pVarTP.x += vv * z.re;
pVarTP.y += vv * z.im;
return;
}