title: Two nested for of for and map?
body: <p>When I need to generate a sequence which needs "two loops", is it better to do something like this:</p>
  
  <pre><code>(for [x (range 1 4)] (map #(* x %) (range 6 9)))
  </code></pre>
  
  <p>or something like this:</p>
  
  <pre><code>(for [x (range 1 4)] (for [y (range 6 9)] (* x y)))
  </code></pre>
  
  <p>Both give the same result:</p>
  
  <pre><code>((6 7 8) (12 14 16) (18 21 24))
  </code></pre>
  
  <p>Is one more idiomatic than the other and what are the differences between these two?</p>
  
  <p>Also, is it possible to get the same result by nesting two <em>map</em>?</p>