[Haskell-cafe] Style and a problem

Hey all, So I have a two part question (I'm new to haskell, so you can throw all your mugs at me). a) I want to write a function that generates lists of lists of size $n$. All having the property that sum lst = sum [1..n]. a-1) After that, I want to remove all permutations. My idea of doing this is to get all lists from the first function and create a new list with the property that "if sorted list A is not in the list, add it." b-2) I think that's too much questions, but I want to get the hang of this quickly (it was kickass for the few things I've tried out). Thanks, \/\/