Arithmetic & Number Theory

Fibonacci Number

The nth Fibonacci number (F₀=0, F₁=1).

Formula

Formula
Fn = Fn−1 + Fn−2

Variables

SymbolDefinitionType & rangeUnitsRole
n index integer (ℤ) input
Fₙ n-th Fibonacci number computed result result

Try it yourself

Interactive calculator
Result

Worked examples

Example 1
Givenn = 20
Result6765
Example 2
Givenn = 30
Result832040