Haskellでよくある primes = [2, 3] ++ filter (\n -> all (\p -> mod n p /= 0) $ takeWhile (\p -> p*p <= n) primes) [5, 7 ..] 的なやつを。 let infty n m = Seq.initInfinite (fun i -> n + i * m) let rec primes = seq { yield! [2; 3] for i in inf…