pyth n = [ (a, b, c) | a <- [1 ..n-2] , b <- [a+1..n-1] , c <- [b+1..n ] , a + b + c <= n , a^2 + b^2 == c^2 ]
(3,4,5) (5,12,13) (6,8,10) (7,24,25) (8,15,17) (9,12,15) (9,40,41) (10,24,26) (12,16,20) (12,35,37) (15,20,25) (15,36,39) (16,30,34) (18,24,30) (20,21,29) (21,28,35) (24,32,40)