def run(target=8):
pgen = eu.GenFinder(eu.gen_primes())
# Loop over all prime numbers
for prime_idx in eu.numbers():
curr_prime = pgen[prime_idx]
curr_digits = eu.digits(curr_prime) # digits in current prime
# Get all selections of indices from current digits
for rindices in eu.selections(range(len(curr_digits))):
rzero = 0 in rindices
if len(rindices) == 0:
continue
found_primes = []
work_digs = curr_digits[:] # copy digits of current prime
# Choose the digit which we will insert at each index in rindices (the current selection)
for replacement in range(10):
if replacement == 0 and rzero:
continue
for rindex in rindices:
work_digs[rindex] = replacement
prime_idx = pgen.find(eu.undigits(work_digs))
if prime_idx != -1:
found_primes.append(pgen[prime_idx])
if len(found_primes) >= target:
# print "answer =",min(found_primes),found_primes,rindices
return min(found_primes)
def run():
ts = euler_util.GenFinder(twice_squares())
primes = euler_util.GenFinder(euler_util.gen_primes())
for i in euler_util.numbers(9, 2):
if primes.contains(i):
continue
if not find_sum(i, ts, primes):
print i
return
def run():
pgen = euler_util.gen_primes()
# initialize primes list with single-digit primes...we don't consider those for rotation
primes = [pgen.next(), pgen.next(), pgen.next(), pgen.next()]
results = []
while len(results) < 11:
prime = pgen.next()
primes.append(prime)
if curious(prime, primes):
print prime
results.append(prime)
print sum(results)
import euler_util
def f(n, a, b):
return (n ** 2) + (a * n) + b
prime_gen = euler_util.gen_primes()
primes = [prime_gen.next() for i in range(1000)]
def count_primes(a, b):
sum = 0
for n in euler_util.numbers():
val = f(n, a, b)
while val > primes[-1]:
primes.append(prime_gen.next())
if not val in primes:
return sum
sum += 1
def run():
max_count = 0
max_a = 0
max_b = 0
for a in range(-999, 1000):
for b in range(-999, 1000):
count = count_primes(a, b)
if count > max_count: