forM_ [1..n] $ \i ->
20
1 is a prime? True 2 is a prime? True 3 is a prime? True 4 is a prime? False 5 is a prime? True 6 is a prime? False 7 is a prime? True 8 is a prime? False 9 is a prime? False 10 is a prime? False 11 is a prime? True 12 is a prime? False 13 is a prime? True 14 is a prime? False 15 is a prime? False 16 is a prime? False 17 is a prime? True 18 is a prime? False 19 is a prime? True 20 is a prime? False