z^{n} = (x^{n} - (\frac{n}{2}) x^{n - 2} y^{2} + (\frac{n}{4}) x^{n - 4} y^{4} - \dots) + i ((\frac{n}{1}) x^{n - 1} y - (\frac{n}{3}) x^{n - 3} y^{3} + \dots)