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))
'''
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
''' 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
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:
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
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
