title: Non-repetitive random number
body: <p>To generate Random numbers from 1- 20 I need to pick selective and it should not be repetitive.</p>
  
  <p>How to do this in C#</p>
  
  <p>Note I need to loop through as like this</p>
  
  <pre><code>Random rnd = new Random()
  rnd.Next(1,20)
  for(int i =0; i&lt;=20;i++)
  {
  
  }
  </code></pre>
  
  <p>For all the loops number should be 1 to 20</p>