title: How to print Alternate A.P and G.P series in Python
body: <p>I want to print Alternate A.P and G.P series like:</p>
  
  <pre><code>- 2 2 4 6 6 18 8 54 10 162 12 486... i.e (A1 G1 A2 G2 A3 G3 .....)
  </code></pre>
  
  <p>here variable is with literal meaning asinged below.
  I found in form of </p>
  
  <pre><code>[(2, 2), (4, 6), (6, 18), (8, 54), (10, 162), (12, 486), (14, 1458), 
   (16, 4374), (18, 13122), (20, 39366)]
  </code></pre>
  
  <p>How can I find as expected?</p>
  
  <pre><code>a,d,r,length=2,2,3,10
  lst=[( a+(n-1)*d, a*r**(n-1) ) for n in range(1,length+12)]
  print(lst)
  </code></pre>