title: Add a series of values into a file using awk or sed
body: <p>I want to insert a column the following file using awk. File structure:</p>
  
  <p><code>1.05228541071
   1.04732408695
   1.04255736847
   1.03783173687
   1.03314654421
   1.02850114709
  ...</code></p>
  
  <p>I was using the following command to add a column (from 0 days).</p>
  
  <p><code>awk '{print x+0, $1; x+=73}' file &gt;file_vs_days</code></p>
  
  <p>And I get the following result for each row:</p>
  
  <p>file_vs_days:</p>
  
  <p><code>0 1.05228541071
  73 1.04732408695
  146 1.04255736847
  219 1.03783173687
  292 1.03314654421
  365 1.02850114709
  ...</code></p>
  
  <p>My problem is in the next row (7th), I want it to start at 365 instead of 365 + 73. </p>
  
  <p>For example:</p>
  
  <pre><code>0 1.05228541071
  73 1.04732408695
  146 1.04255736847
  219 1.03783173687
  292 1.03314654421
  365 1.02850114709
  365 x7 
  (365+1*73) x8
  (365+2*73) x9
  (365+3*73) x10
  (365+4*73) x11
  (365+5*73) x12
  ...
  </code></pre>
  
  <p>How can I modify the command to print the values every 6 rows?.</p>
  
  <p>Thanks in advance.</p>