1. The problem is to understand what a Fibonacci sequence is. 2. A Fibonacci sequence is a series of numbers where each number is the sum of the two preceding ones, usually starting with 0 and 1. 3. The formula for the Fibonacci sequence is: $$F_n = F_{n-1} + F_{n-2}$$ where $F_0 = 0$ and $F_1 = 1$. 4. This means: - The 0th term is 0. - The 1st term is 1. - Every term after that is the sum of the two terms before it. 5. For example, the first few terms are: $$0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...$$ 6. This sequence appears in many natural phenomena and has important applications in mathematics and computer science.