Question

Which type of sequence requires you to use the previous two terms in order to find the next term?

Answer 1

A recursive sequence.

For example, the Fibonacci sequence is a sequence that is generated by adding two starting values together to create a third value; then the fourth is the sum of the second and third, the fifth is the sum of the third and fourth, and so on.

Recursively, it's defined as

$\begin{cases}F_1=1\\F_2=1\\F_{n+2}=F_{n+1}+F_n&\text{for }n\ge3\end{cases}$