title: excluding words with consecutive repeat characters
body: <p>Say I have a list of words like this: mouse, abba, roar, accent</p>
  
  <p>I need a regex that will match mouse and roar, but not abba or accent, because the last two have consecutive repeat characters (bb and cc).  </p>
  
  <p>I managed to come up with the following pattern to match only the words WITH double consecutive characters:</p>
  
  <pre><code>.*(.)\1.*
  </code></pre>
  
  <p>However what I need is the opposite, but I am having a hard time inverting it.</p>