Can Fibonacci numbers be negative?

Updated Apr 28, 2026

Short answer

Standard sequences are positive, but 'nefaboracci' extends into negatives.

Deep explanation

The Fibonacci sequence is defined by the recurrence relation $F_n = F_{n-1} + F_{n-2}$. Standard sequences are positive, but 'nefaboracci' extends into negatives.

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?

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