Here is a plot of
$$\frac{1}{100}\left(\sum_{k=0}^{16}\frac{x^k}{\sqrt{k!}}\right)$$
on the interval $[-4,0]$. (Above I added the terms up to degree $16$.)
Next, is a plot of
$$\frac{1}{100}\left(\sum_{k=0}^{15}\frac{x^k}{\sqrt{k!}}\right)$$
on the interval $[-3,0]$. (Above I added the terms up to degree $15$)
This is one strange series.
