Simple example of an observable sequence of integers.

SimpleRxDemo.cs

var xs = Observable.Range(1, 10)
                   .Select(x => x + 1)
                   .Where(x => x % 3 == 0);

xs.ObserveOn(Scheduler.Default).Subscribe(
  el => Console.WriteLine("Got element: {0}", el),
  ex => Console.WriteLine("Error: {0}", ex.Message),
  () => Console.WriteLine("Completed.")
);