Sequences as Functions and Recursion Practice Test

A function $f$ is defined on the integers $n=1,2,3,\dots$ by $f(1)=2$ and $f(n+1)=3,f(n)$ for $n\ge 1$. What is $f(4)$?

The sequence $a_n$ is a function with domain $n=1,2,3,\dots$ and starts $6, 3, 0, -3, \dots$. Which recursive rule generates this sequence?