I'm confused about behavior of this series :$\sum_{n=k}^{+\infty} n^{-\frac{n}{\log n}}$ with $k$ is natural number , for $k=0 ,1$ the series converges according to wolfram alpha assumption however $k=0 ,1$ are singular points , Now I want to know more about behavior of that series playing with values of the integer $k$ , for $k=1$ the series converges and it gives:
$$\sum_{n=1}^{+\infty} n^{-\frac{n}{\log n}}=\frac{1}{e-1}\tag{1}$$ and for $k=2$ we have : $$\sum_{n=2}^{+\infty} n^{-\frac{n}{\log n}}=\frac{1}{(e-1)e}\tag{2}$$ and for $k=3$ we have : $$\sum_{n=3}^{+\infty} n^{-\frac{n}{\log n}}=\frac{1}{(e-1)e^2}\tag{3}$$ , I have conjuctered that : $$\sum_{n=k}^{+\infty} n^{-\frac{n}{\log n}}=\frac{1}{(e-1)e^{k-1}}\tag{4}$$ , Now I have tow question :
Question:01 : Why wolfram alpha assumed that series converges for $k=0,1$ however they are singular points ?
Question:02
Does what i have conjuctered in $4$ true ?
Hint. The series is geometric: for $ n> 1$, $$n^{-\frac{n}{\log n}}=\exp\left(-\frac{n}{\log n}\cdot \log(n)\right)=(1/e)^n.$$