# Fibonacci number

From Free Pascal wiki

# Fibonacci number

The Fibonacci Sequence is the series of numbers:

0, 1, 1, 2, 3, 5, 8, 13, 21, ...

The idea is to add the two last numbers, and thus get the next value.

## Recursive way

```
function FibonacciNumber( n : integer ): integer;
begin
if n = 0 then result := 0
else
if n = 1 then result := 1
else result := ( FibonacciNumber( n - 1 ) + FibonacciNumber( n - 2) );
end;
```