For which values of xxx does the series ∑n=1∞xnnn\sum_{n=1}^{\infty} \frac{x^n}{n^n}∑n=1∞nnxn converge?
x=0x=0x=0
∣x∣<1|x| < 1∣x∣<1
All real xxx
∣x∣<e|x| < e∣x∣<e