List comprehension in Haskell, Python and Ruby

Question

I have started looking at the project Euler site as a way to learn Haskell, and improve my Python and Ruby. I think the Haskell and Python versions are ok, but I\'m sure the

Answer 1

Not a list comprehension, I know, but to solve that I would use:

3*((999/3)**2+999/3)/2+5*((999/5)**2+999/5)/2-15*((999/15)**2+999/15)/2

Faster then any list comprehension one might come up with, and works in any language ;)

Only posting to show another way of looking at the same problem using http://en.wikipedia.org/wiki/Summation.