Ejemplo n.º 1
0
def totients(n):
    '''
    Generates the phi array of Euler's totient function
    up to n, using sieving method.
    '''
    prime = primes.prime_list(n)
    phi = [float(i) for i in range(n + 1)]
    for p in range(2, n + 1):
        if prime[p]:
            j = 1
            while j * p <= n:
                phi[p * j] *= 1.0 - 1.0 / p
                j += 1
    return list(map(round, phi))
Ejemplo n.º 2
0
'''
Project Euler #7

Find the 10001st Prime
'''

from primes import prime_list

primes = prime_list(500000)

prime_count = 1
x = 2
while x < 100001:
    x += 1
    if primes[x]:
        prime_count += 1

print x
Ejemplo n.º 3
0
'''
Project Euler #7

Find the 10001st Prime
'''

from primes import prime_list

primes = prime_list(500000)

prime_count = 1
x = 2
while x < 100001:
	x += 1
	if primes[x]:
		prime_count += 1

print x
Ejemplo n.º 4
0
import math

from primes import is_prime_c as is_prime
from primes import prime_list

l = 8500
primes_list = [3] + prime_list(l)[3:]
len_primes_list = len(primes_list)

def pair_prime(a, b):
    return is_prime(int(a + b)) and is_prime(int(b + a))

def f():
    M = l * 5
    for c1 in xrange(len_primes_list - 4):
        p1 = primes_list[c1]
        s1 = str(p1)
        for c2 in xrange(c1, len_primes_list - 3):
            p2 = primes_list[c2]
            t2 = p1 + p2
            s2 = str(p2)
            if pair_prime(s1, s2):
                for c3 in xrange(c2, len_primes_list - 2):
                    p3 = primes_list[c3]
                    t3 = t2 + p3
                    s3 = str(p3)
                    if pair_prime(s1, s3) and pair_prime(s2, s3):
                        for c4 in xrange(c3, len_primes_list - 1):
                            p4 = primes_list[c4]
                            t4 = t3 + p4
                            if (t4 + p4) >= M:
Ejemplo n.º 5
0
import primes, time

start = time.time()

x = primes.prime_list(2000000)

total = 0
for i in xrange(1, 2000000):
	if x[i]:
		total += i

print total, time.time() - start
Ejemplo n.º 6
0
import primes, time

start = time.time()

x = primes.prime_list(2000000)

total = 0
for i in xrange(1, 2000000):
    if x[i]:
        total += i

print total, time.time() - start