\sum_{n=1}^{\pi}(-1)^{n} \frac{\sqrt{n}}{1+2 \sqrt{n}} \sum_{n=1}^{x}(-1)^{n} \cos \left(\frac{\pi}{n}\right) \sum_{n=1}^{x}(-1)^{n+1} \frac{n^{2} 2^{n}}{n !} \text { d.) } \sum_{n=2}^{x}\left(\frac{-2 n}{n+1}\right)^{5 n} \sum_{k=2}^{x} \frac{5^{k}}{3^{k}+4^{k}} \sum_{n=2}^{x} \frac{1}{(\ln n)^{\ln n}}