title: How do I make an Observable Interval start immediately without a delay?
body: <p>I want my observable to fire immediately, and again every second. <a href="http://reactivex.io/documentation/operators/interval.html" rel="noreferrer"><code>interval</code></a> will not fire immediately. I found <a href="https://stackoverflow.com/questions/36612945/how-to-get-an-observable-to-return-data-immediately-and-every-5-seconds-thereaft">this question</a> which suggested using <code>startWith</code>, which DOES fire immediately, but I then get a duplicate first entry.</p>
  
  <pre><code>  Rx.Observable.interval(1000).take(4).startWith(0).subscribe(onNext);
  </code></pre>
  
  <p><a href="https://plnkr.co/edit/Cl5DQ7znJRDe0VTv0Ux5?p=preview" rel="noreferrer">https://plnkr.co/edit/Cl5DQ7znJRDe0VTv0Ux5?p=preview</a></p>
  
  <p>How can I make interval fire immediately, but not duplicate the first entry? </p>