hamming = 1 : foldr u [] [2,3,5] where
        u n s = -- fix (merge s . map (n*) . (1:))
                r where
                r = merge s (map (n*) (1:r))

merge [] b = b
merge a@(x:xs) b@(y:ys) | x < y     = x : merge xs b
                        | otherwise = y : merge a ys

main = do
	print $ take 20 (hamming ())
	print $ (hamming ()) !! 1690
	print $ (hamming ()) !! (1000000-1)