Sieve of Eratosthenes
Find all the prime numbers less than or equal to k.
Python
import functools k=1000 def sieve (k): def f (p, lst): s = list (filter (lambda i : i%p != 0 or i/p == 1, lst)) r = list (filter (lambda i : i > p, s)) if len (r) == 0: return s else: return f (r[0], s) return f (2, range (2, k + 1)) print (str(sieve (k)))