def factor_sidi(self, i):
        # sidi analogon to levin (factorial series)
        # [1] p.59,e.8.3-16 (with n-j replaced by i)
        return (self.theta + self.n - 1) * (self.theta + self.n - 2) / self.ctx.mpf((self.theta + 2 + self.n - i - 2) * (self.theta + 2 * self.n - i - 3))
dataset/ETHPy150Open fredrik-johansson/mpmath/mpmath/calculus/extrapolation.py/levin_class.factor_sidi/operator `*` -> `+`