title: Regex repeating numbers and sequences
body: <p>Another Regex question. Have spend ages trawling through StackOverflow with no joy.</p>
  
  <p>I need regexs (regexai?) for the following:</p>
  
  <ul>
  <li>Can’t have more than 4 double numbers in a row. Eg 22334455 fails,</li>
  <li>Can’t have a sequence of numbers longer than or equal to 5 digits. Eg
  12345 or 56789 both fail,</li>
  <li>Must have 4 or more different digits. Eg
  77788778877 fails</li>
  </ul>
  
  <p>I don't expect one expression to fit all, guessing it'll probably be 2/3 required.</p>
  
  <p>Cheers</p>