@cacheit
    def coeff(self, pt):
        if pt < self.start or pt > self.stop:
            raise IndexError("Index %s out of bounds %s" % (pt, self.interval))
        return self._eval_coeff(pt)
Returns the coefficient at point pt
dataset/ETHPy150Open sympy/sympy/sympy/series/sequences.py/SeqBase.coeff