def eratosthenes(n):
    prime_list = list(range(2,n+1))
    for i in prime_list:
        j=2
        while i*j <= prime_list[-1]:
            if i*j in prime_list:
                prime_list.remove(i*j)
            j = j+1
    return prime_list


def sundaram(n):
    prime_list = list(range(1,n+1))
    i,j = 1,1
    for j in range(1,n+1):
        for i in range(1,j+1):
            if i+j+2*i*j in prime_list:
                prime_list.remove(i+j+2*i*j)
        j = j+1

    k = 0

    while k < len(prime_list):
        prime_list[k] = 2*prime_list[k] +1
        k = k+1

    print(prime_list)