Euler #187

def primes_sieve(limit):
    a = [True] * limit
    a[0] = a[1] = False

    for (i, isprime) in enumerate(a):
        if isprime:
            yield i
            for n in range(i*i, limit, i):
                a[n] = False

primes, nums = list(primes_sieve(int((10**8)/2))), []

for a in primes:
    print(a)
    for b in primes:
        if a*b >= 10**8:
            break
        else:
            nums.append(a*b)
print(len(set(nums)))