Answer
Exponential decay function.
Work Step by Step
For $x$.
$0+1=1$
$1+1=2$
$2+1=3$
For $y$.
$\frac{64}{4}=16$
$\frac{16}{4}=4$
$\frac{4}{4}=1$
As $x$ increases by $1,$ $y$ is divided by $4$.
So, the function is exponential decay.