euler/python/e027.py

from lib_prime import primes, is_prime


def number_consecutive_primes(a, b):
    def formula(n):
        return n * n + a * n + b
    n = 0
    while True:
        if not is_prime(formula(n)):
            return n
        n += 1


def euler_027():
    n_max, a_max, b_max = 0, 0, 0
    for b in primes(1000):
        for a in range(-999, 1000):
            a = -1 * a
            n = number_consecutive_primes(a, b)
            if n > n_max:
                n_max, a_max, b_max = n, a, b
    return a_max * b_max


if __name__ == "__main__":
    print("e027.py: {}".format(euler_027()))
    assert(euler_027() == -59231)