import Data.List

factor :: Integer -> [Integer]
factor 1 = []
factor n = let prime = head $ dropWhile ((/= 0) . mod n) [2 .. n]
           in (prime :) $ factor $ div n prime

count :: Eq a => [a] -> [(a, Int)]
count xs = map (\l -> (head l, length l)) $ group xs

p :: Integer -> Double
p nInt = 1/n * product fractions
    where
        fractions = map fraction factors
        fraction :: (Double, Int) -> Double
        fraction (pi, ri) = (pi + fromIntegral ri * (pi - 1)) / pi
        factors = map (\(p, r) -> (fromIntegral p, fromIntegral r)) $
                      count (factor nInt)
        n = fromIntegral nInt

main :: IO ()
main = print $ map p [1..10]