estimating using fibonacci code example

Example 1: fibonacci sequence

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...

Example 2: program to get the Fibonacci series

public class Fibonacci {

    public static void main(String[] args) {

        int i = 1, n = 10, t1 = 0, t2 = 1;
        System.out.print("First " + n + " terms: ");

        while (i <= n)
        {
            System.out.print(t1 + " + ");

            int sum = t1 + t2;
            t1 = t2;
            t2 = sum;

            i++;
        }
    }
}