Числа Фибоначчи. Рекурсия

class Fibonacci
{
    static void Main()
    {
        long[] arr = new long[20];
        for (int i = 0; i < arr.Length; ++i)
        {
            arr[i] = Fib(i + 1);
            System.Console.Write(arr[i] + " ");
        }
        System.Console.WriteLine();
    }

    static long Fib(int number)
    {
        if (number == 1)
        {
            return 1;
        }
        if (number == 2)
        {
            return 1;
        }
        return Fib(number - 1) + Fib(number - 2);
    }
}