title: Euler 75 what is wrong, I have all primitive triangles and multiples but still something fails
body: <ul>
  <li><p>Basetri looks just like the wikipedia definition of the euclidian
  algorithm (but i only save perimeter) , and seems to generate all
  triangles.</p></li>
  <li><p>Timesify gives all multiples of these triangles (the 120 triangle
  appears 3 times)</p></li>
  <li><p>Then i concatenate, sort and group to give list of lists with each of
  the perimeters in same group, then filter the ones with more than 1
  just one way to make the perimeter.</p></li>
  </ul>
  
  <p>This should give me all the triangles that are just possible to do in just one way, however  <code>length euler75 = 157730</code> does not seem to be the valid answer.</p>
  
  <pre><code>euler75 = filter justOneElement $ group $ sort $ concat $ timesify (takeWhile (&lt;=1500000) basetri)
  
  justOneElement (x:[]) = True
  justOneElement _ = False
  
  basetri = [((x m n + y m n + z m n)) | m&lt;-[1..700],n&lt;-[1..(m-1)], odd (m-n),gcd m n == 1]
      where
          x m n = (m^2 - n^2)
          y m n = 2*m*n
          z m n = (m^2+n^2)
  
  timesify [] = []
  timesify (x:xs) = (takeWhile (&lt;=1500000) $ (map (*x) [1..])) : timesify xs
  </code></pre>