title: Ways to write a number as a sum
body: <p>I want to write for example number 10 all the possible ways as a sum of units 3, 4, ..., n-1 (not 2)
  for example i can write 10 as</p>
  
  <pre><code>10=10(units)
  10=7 + 1*3 or 
  10=4 + 2*3 or
  10=3 + 1*3 + 1*4 or
  10=2 + 2*4 or ....
  </code></pre>
  
  <p>I dont care about the number of combinations!
  I want the combinations!!! I mean an algoithm to output like this</p>
  
  <pre><code>un 3 4 5 6 7 8 9 10
  -------------------
  10 0 0 0 0 0 0 0 0
  07 1 0 0 0 0 0 0 0 
  04 2 0 0 0 0 0 0 0 
  03 1 1 0 0 0 0 0 0 
  02 0 2 0 0 0 0 0 0   etc
  </code></pre>
  
  <p>any response is welcomed!!!</p>