The Maclaurin series for 1/(1−x)21/(1-x)^21/(1−x)2 is?
∑n=1∞nxn−1\sum_{n=1}^{\infty} n x^{n-1}∑n=1∞nxn−1
∑n=0∞nxn\sum_{n=0}^{\infty} n x^n∑n=0∞nxn
∑n=1∞nxn\sum_{n=1}^{\infty} n x^n∑n=1∞nxn
∑n=0∞xn\sum_{n=0}^{\infty} x^n∑n=0∞xn