1.
The sum of the series r=0n(1)rrnCr(12r+3r22r+7r23r+15r24r+ m terms)\sum_{r=0}^{n} (-1)^{r} r \cdot {}^nC_{r} \left( \frac{1}{2^{r}} + \frac{3^{r}}{2^{2r}} + \frac{7^{r}}{2^{3r}} + \frac{15^{r}}{2^{4r}} + \ldots \text{ m terms} \right) is