calculate uniques in draw 10 from deck of cards

using System;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var counts = new long[11];

            for (var _A = 0; _A <=  4; ++_A)
            for (var _2 = 0; _2 <=  4; ++_2)
            for (var _3 = 0; _3 <=  4; ++_3)
            for (var _4 = 0; _4 <=  4; ++_4)
            for (var _5 = 0; _5 <=  4; ++_5)
            for (var _6 = 0; _6 <=  4; ++_6)
            for (var _7 = 0; _7 <=  4; ++_7)
            for (var _8 = 0; _8 <=  4; ++_8)
            for (var _9 = 0; _9 <=  4; ++_9)
            for (var _T = 0; _T <= 16; ++_T)
            {
                if ((_A + _2 + _3 + _4 + _5 + _6 + _7 + _8 + _9 + _T) != 10) continue;

                var unique = 0;

                unique += _A != 0 ? 1 : 0;
                unique += _2 != 0 ? 1 : 0;
                unique += _3 != 0 ? 1 : 0;
                unique += _4 != 0 ? 1 : 0;
                unique += _5 != 0 ? 1 : 0;
                unique += _6 != 0 ? 1 : 0;
                unique += _7 != 0 ? 1 : 0;
                unique += _8 != 0 ? 1 : 0;
                unique += _9 != 0 ? 1 : 0;
                unique += _T != 0 ? 1 : 0;

                var weight = 1L;

                weight *= Combin( 4, _A);
                weight *= Combin( 4, _2);
                weight *= Combin( 4, _3);
                weight *= Combin( 4, _4);
                weight *= Combin( 4, _5);
                weight *= Combin( 4, _6);
                weight *= Combin( 4, _7);
                weight *= Combin( 4, _8);
                weight *= Combin( 4, _9);
                weight *= Combin(16, _T);

                counts[unique] += weight;
            }

            Console.WriteLine(" 1 = {0:#,##0}", counts[ 1]);
            Console.WriteLine(" 2 = {0:#,##0}", counts[ 2]);
            Console.WriteLine(" 3 = {0:#,##0}", counts[ 3]);
            Console.WriteLine(" 4 = {0:#,##0}", counts[ 4]);
            Console.WriteLine(" 5 = {0:#,##0}", counts[ 5]);
            Console.WriteLine(" 6 = {0:#,##0}", counts[ 6]);
            Console.WriteLine(" 7 = {0:#,##0}", counts[ 7]);
            Console.WriteLine(" 8 = {0:#,##0}", counts[ 8]);
            Console.WriteLine(" 9 = {0:#,##0}", counts[ 9]);
            Console.WriteLine("10 = {0:#,##0}", counts[10]);
            Console.ReadLine();
        }

        static int Combin(int n, int k)
        {
            if (k > n) return 0;
            if (n == k) return 1;
            if (k > (n - k)) k = n - k;

            var num = 1;
            var den = 1;

            for (var z = 1; z <= k; --n, ++z)
            {
                num *= n;
                den *= z;

                if ((num % den) == 0)
                {
                    num /= den; den = 1;
                }
            }

            return num / den;
        }
    }
}