yield (C# Reference)

http://msdn.microsoft.com/en-us/library/9k7k7cf0.aspx

 

public class PowersOf2
{
    public static System.Collections.IEnumerable Power(int number, int exponent)
    {
        int counter = 0;
        int result = 1;
        while (counter++ < exponent)
        {
            result = result * number;
            yield return result;
        }
    }

    static void Main()
    {
        // Display powers of 2 up to the exponent 8:
        foreach (int i in Power(2, 8))
        {
            Console.Write("{0} ", i);
        }
    }
}
/*
Output:
2 4 8 16 32 64 128 256
*/