Project Euler #46

euler46.py

from itertools import takewhile, count, imap
from math import sqrt
from operator import and_

def twicesq(n):
    return takewhile(lambda x: x < n,
                (x * x * 2 for x in count(1)))

def isprime(n):
    for x in range(2, int(sqrt(n)) + 1):
        if n % x == 0:
            return 0
    return 1

print (i for i in count(1)
            if i % 2 != 0 and not isprime(i)
                    and reduce(and_, imap(lambda b: not isprime(b),
                        imap(lambda j: i - j,
                            (j for j in twicesq(i)))), 1)).next()