Compute the sum of the first n even fibonacci numbers

Computes the first n even numbers from the fibonacci sequence using 2 methods and compares their results.

Usage: fibonacci n

Args: - n: number (n > 0) of even fibonacci numbers to compute

$ ./fibonacci 6
Testing both methods: loops vs no loops
0: 0 0
1: 2 2
2: 2 2
3: 10 10
4: 10 10
5: 10 10
6: 10 10
Results: Outputs match 100 %
This is due to precision loss when using our second "no loops" method