# 6.4 $\pi”[x]$: Second-Order Derivative of Base Prime Counting Function

The first plot below illustrates $\pi”[0]=0$ and $\pi”[x]$ is an odd function of x. The next three plots illustrate $\pi”[x]$ in the right=half plane at $f={1, 2, 3}$. The last plot below focuses around $x=19$ with evaluation frequencies $f={2, 4, 8}$.