Fibonacci Sequence Generator

Fibonacci numbers grow exponentially, and regular JavaScript numbers lose exact integer precision above Number.MAX_SAFE_INTEGER (2^53 - 1) — which the sequence exceeds by around the 79th term. Using BigInt keeps every term in the sequence exact even at the maximum 1,000-term limit.

F(0)=0 starts the sequence as 0, 1, 1, 2, 3, 5... (the standard mathematical convention), while F(1)=1 skips the leading zero and starts as 1, 1, 2, 3, 5... — both are common conventions depending on the textbook or context.

It divides the last generated term by the second-to-last term — as the sequence grows longer, this ratio converges toward the golden ratio φ ≈ 1.6180339887, a well-known mathematical property of the Fibonacci sequence.

Yes, the tool caps generation at 1,000 terms to keep the output readable and the computation instant — that's already far more terms than almost any practical use case needs.

Yes — set the number of terms to the index you want (remembering whether you started counting from F(0) or F(1)) and read the last value in the generated sequence.