def main(): primes = make_primes(10000) primes.remove(2) all_five_primes = combinations(primes, 5) for p in all_five_primes: if a_set_of_five_primes(p): print sum(p) return
#!/usr/bin/python # coding: UTF-8 """ @author: CaiKnife Prime permutations Problem 49 The arithmetic sequence, 1487, 4817, 8147, in which each of the terms increases by 3330, is unusual in two ways: (i) each of the three terms are prime, and, (ii) each of the 4-digit numbers are permutations of one another. There are no arithmetic sequences made up of three 1-, 2-, or 3-digit primes, exhibiting this property, but there is one other 4-digit increasing sequence. What 12-digit number do you form by concatenating the three terms in this sequence? """ from itertools import permutations from euler import make_primes, is_prime, get_digits def to_tuple(n): return tuple(str(n)) primes = [p for p in make_primes(10000) if len(str(p)) == 4] primes = [p for p in primes if is_prime(p + 3330) and len(str(p + 3330)) == 4 and is_prime(p + 6660) and len( str(p + 6660)) == 4] for p in primes: per = permutations(to_tuple(p)) if to_tuple(p + 3330) in per and to_tuple(p + 6660) in per: print p, p + 3330, p + 6660
9 = 7 + 212 15 = 7 + 222 21 = 3 + 232 25 = 7 + 232 27 = 19 + 222 33 = 31 + 212 It turns out that the conjecture was false. What is the smallest odd composite that cannot be written as the sum of a prime and twice a square? """ from euler import is_prime, make_primes from itertools import product PRIMES = make_primes(10000) def is_conjecture(n): if is_prime(n): return False if not n % 2: return False c = product(PRIMES, [2 * i ** 2 for i in range(1, 100)]) for p in c: if n == p[0] + p[1]: return True return False for i in range(9, 10000):