title: Repeating a repeated sequence
body: <p>We want to get an array that looks like this:</p>
  
  <pre><code>1,1,1,2,2,2,3,3,3,4,4,4,1,1,1,2,2,2,3,3,3,4,4,4,1,1,1,2,2,2,3,3,3,4,4,4
  </code></pre>
  
  <p>What is the easiest way to do it?</p>