C#

Observable.Range(0, 10).
    Select(e => (Task.Factory.StartNew(() => DoWork(e),
                                            CancellationToken.None,
                                            TaskCreationOptions.DenyChildAttach,
                                            TaskScheduler.Default)))
    .ObserveOnDispatcher()
    .Subscribe(evt =>
    {
       //Do something with evt.Result
    });

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

namespace OddNumbers
{
    class Program
    {
        static void Main(string[] args)
        {
            WriteNumbers(EvenNumbers(100, 1000), 10);
            Console.ReadKey();

            WriteNumbers(OddNumbers(100, 1000), 10);
            Console.ReadKey();
        }

        static void WriteNumbers(IEnumerable<int> numbers, int numbersPerLine)
        {
            Debug.Assert(numbers != null);
            Debug.Assert(numbersPerLine >= 1);

            StringBuilder line = new StringBuilder();
            int count = 0;

            Action writeLine = () =>
            {
                Console.WriteLine(line.ToString());
                line.Clear();
                count = 0;
            };

            foreach (int number in numbers)
            {
                line.Append(number).Append(", ");

                count++;

                if (count == numbersPerLine)
                    writeLine();
            }

            if (count > 0)
                writeLine();
        }

        static IEnumerable<int> EvenNumbers(int start, int end)
        {
            Debug.Assert(start <= end);

            if (IsOdd(start))
                start++;

            for (int i = start; i <= end; i += 2)
                yield return i;
        }

        static IEnumerable<int> OddNumbers(int start, int end)
        {
            Debug.Assert(start <= end);

            if (!IsOdd(start))
                start++;

            for (int i = start; i <= end; i += 2)
                yield return i;
        }

        static bool IsOdd(int number)
        {
            return (number & 1) == 1;
        }
    }
}

MadDashCoder wrote:

for (int i = 100; i <= 10000; i++)
{
    if (IsOddNumber(i))
    {
        OddNumbers.Append(i).Append(comma);
    }
}

for (int i = 101; i < 10000; i += 2)
{
    OddNumbers.Append(i).Append(comma);
}