title: Excel - Fill rows with certain step
body: <p>I am really finding this weirdly hard to explain but I want to perform a rows automatic fill operation in excel and I am having this problem.
  I have these rows:</p>
  
  <pre><code>1 = A1
  2 = D1
  3 = G1
  4 = J1
  5 = M1
  6 = O1
  </code></pre>
  
  <p>I want to repeat this sequence so that 7 = A2, 8 = D2 etc. Auto fill completes 7 as A7, 8 as D7, a 6 cell step insted of 1.</p>
  
  <p>What am I doing wrong?</p>