# Fibonacci Sequence

suggest changeYou can calculate a number in the Fibonacci sequence using recursion.

Following the math theory of F(n) = F(n-2) + F(n-1), for any i > 0,

```
// Returns the i'th Fibonacci number
public int fib(int i) {
if(i <= 2) {
// Base case of the recursive function.
// i is either 1 or 2, whose associated Fibonacci sequence numbers are 1 and 1.
return 1;
}
// Recursive case. Return the sum of the two previous Fibonacci numbers.
// This works because the definition of the Fibonacci sequence specifies
// that the sum of two adjacent elements equals the next element.
return fib(i - 2) + fib(i - 1);
}
fib(10); // Returns 55
```

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