Fibonacci CalculatorGenerate the Fibonacci sequence up to N terms with exact BigInt precision.

The Fibonacci sequence is generated iteratively using JavaScript BigInt for exact arbitrary-precision integer arithmetic. The iterative approach (vs. naive recursion) runs in O(n) time and O(n) space, compared to O(2^n) for naive recursion. The sequence grows approximately exponentially with ratio φ ≈ 1.618: F(n) ≈ φⁿ/√5. This means the number of digits in F(n) is approximately n × log₁₀(φ) ≈ n × 0.209. At n = 500, F(500) has about 105 digits. Binet's formula gives an exact closed-form: F(n) = (φⁿ − ψⁿ)/√5 where ψ = (1−√5)/2 ≈ −0.618, but floating-point imprecision makes this unreliable for large n, which is why this calculator uses iterative BigInt computation instead. Notable Fibonacci properties include: every third number is even, GCD(F(m), F(n)) = F(GCD(m,n)), and the sum of the first n Fibonacci numbers equals F(n+2) − 1.