7 lines
186 B
OCaml
7 lines
186 B
OCaml
let is_prime n =
|
|
let rec test x =
|
|
x * x > n || n mod x <> 0 && n mod (x + 2) <> 0 && test (x + 6)
|
|
in
|
|
if n < 5
|
|
then n lor 1 = 3
|
|
else n land 1 <> 0 && n mod 3 <> 0 && test 5
|