Fibonacci Sequence Calculator

Fibonacci.cs

public class Fibinocci
{
    public readonly int N;

    public Fibinocci(int n)
    {
        if (n < 0)
        {
            throw new Exception("n must be >= 0");
        }

        this.N = n;
    }

    public int Calculate()
    {
        if (this.N == 0)
        {
            return 0;
        }

        return Calculate(0, 1, 1);
    }

    internal int Calculate(int previous, int current, int count)
    {
        if (count == this.N)
        {
            return current;
        }

        return this.Calculate(current, previous + current, ++count);
    }
}