def problem49():
result = []
primes = [x for x in prime_generator(10000)]
d = 3330
for n in xrange(1000, 10000):
if n not in primes:
continue
n_str = str(n)
per = [int(permutation(n_str, x)) for x in xrange(factorial(4))]
pri = [x for x in per if x in primes]
if n+d in pri and n+2*d in pri:
result.append(str(n) + str(n+d) + str(n+d+d))
return list(set(result))
def problem37():
max = 1000000
primes = set([x for x in prime_generator(max)])
result = []
def is_truncable_prime(n):
n = str(n)
l = len(n)
for i in xrange(l):
if int(n[l-i-1:]) not in primes or int(n[:i+1]) not in primes:
return False
return True
for x in xrange(10, max):
print x
if is_truncable_prime(x):
result.append(x)
print result, len(result)
return sum(result)
def problem46():
max = 10**4
primes = [x for x in prime_generator(max)]
number = 3
while number < max:
number = number + 2
if number in primes:
continue
valid = 0
for x in primes:
if x >= number:
break
test = number - x
square = sqrt(test/2)
if test%2 == 0 and floor(square) == square:
valid = 1
break
if valid == 0:
return number
return 0
from eulerhelper import prime_generator
limit = 10000
prime_table = [x for x in prime_generator(limit)]
def countprimes(a, b):
count = 0
for n in xrange(limit):
x = n*n + a*n + b
if x > limit:
print "Warning: limit exceeded. a=", a, "b=", b, "n=", n, "x=", x
if x in prime_table:
count = count + 1
else:
break
return count
assert countprimes(1,41) == 40
assert countprimes(-79, 1601) == 80
def problem27():
start = -1000
end = 1000
max = 0
result = (0,0)
for a in xrange(start, end+1):
for b in xrange(start, end+1):
count = countprimes(a, b)
print a, b, count
from eulerhelper import factorial, permutation, prime_generator
primes = [x for x in prime_generator(17)]
def divisiontest(number):
for x in xrange(7):
if int(number[x+1:x+4]) % primes[x] != 0:
return False
return True
assert divisiontest("1406357289")
def problem42():
result = []
pandigit = "0123456789"
for x in xrange(factorial(10)-1):
number = permutation(pandigit,x)
if divisiontest(number):
result.append(int(number))
return sum(result)
print problem42()
