title: OOM exception when generating a large array of strings
body: <p>I'm trying to generate a large amount of strings. In my small sample code it works as intended, but my desired result has a string length of 8, and not 3 like below, which results in an out of memory exception.</p>
  
  <p>Is there any way to run this more efficiently?</p>
  
  <pre><code>string chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
  string numbers = "0123456789";
  var query = from c1 in chars 
              from c2 in chars 
              from d1 in digits 
              select string.Format("{0}{1}{2}", c1, c2, d1);
  string[] possibleCombinations = query.ToArray();
  </code></pre>