''' -The sieve of Eratosthenes is an algorithm used to find prime numbers, less than or equal to a given value. -Illustration: https://upload.wikimedia.org/wikipedia/commons/b/b9/Sieve_of_Eratosthenes_animation.gif ''' from math import sqrt def SOE(n): check = round(sqrt(n)) #Need not check for multiples past the square root of n sieve = [False if i <2 else True for i in range(n+1)] #Set every index to False except for index 0 and 1 for i in range(2, check): if(sieve[i] == True): #If i is a prime for j in range(i+i, n+1, i): #Step through the list in increments of i(the multiples of the prime) sieve[j] = False #Sets every multiple of i to False for i in range(n+1): if(sieve[i] == True): print(i, end=" ")