Return value of the the following polynomial.
        .. math::
           (a * e^(b*steps) - 1) / (e^b - 1)

        :param a: multiplier
        :param b: exponent multiplier
        :param steps: the number of steps

def _sumSeries(a: float, b: float, steps: int) -> float:
        """
        Return value of the the following polynomial.
        .. math::
           (a * e^(b*steps) - 1) / (e^b - 1)

        :param a: multiplier
        :param b: exponent multiplier
        :param steps: the number of steps
        """
        return a * (exp(b * steps) - 1) / (exp(b) - 1)