juniorFibonacci Series
What is the base case in Fibonacci recursion?
Updated Apr 28, 2026
Short answer
if n <= 1: return n.
Deep explanation
The Fibonacci sequence is defined by the recurrence relation $F_n = F_{n-1} + F_{n-2}$. if n <= 1: return n.
Real-world example
Modeling population growth in ideal conditions.
Common mistakes
- Using a 1-based index when the interviewer expects 0-based.
Follow-up questions
- What is the 5th Fibonacci number?