Answer
A recursion formula gives the nth term of a sequence as a function of the previous term.
See below.
Work Step by Step
A recursion formula gives the nth term of a sequence as a function of the previous term.
For example: $a_n=3a_{n-1}+4$
Here, $a_1$ is the initial term and $a_n$ is the each term after the first.
$3a_{n-1}+4$ defines the next term as 3 times the previous term plus $4$.
