title: What is the swift way of creating an Array of numbers of a certain pattern?
body: <p>The pattern of numbers I'm looking to create follows the pattern:</p>
  <p><code>[100, 200, 400, 800, 1600, 3200, 6400]</code></p>
  <p>I know I can accomplish this with a for loop but coming from languages like <code>Python</code> I wonder if there is a <code>Swift</code> way to do this. Thanks.</p>