We can build the **Fibonacci sequence** by starting with a $0$ and a $1$ and then applying a rule: each term of the sequence is the sum of the previous two terms.

That makes the third term $0 + 1 = 1,$ the fourth term $1 + 1 = 2,$ the fifth $1 + 2 = 3,$ and so on:

$0, 1, 1, 2, 3, 5, 8, 13, 21, \ldots$

The terms of the sequence grow larger and larger, but are there any hidden patterns in it? Keep reading to see one, or jump to the challenge for a related question.