from utils import divisors_up_to, window
def are_consecutive(*nums):
return nums == tuple(range(nums[0], nums[-1]+1))
divisors_by_number = divisors_up_to(1_000_000)
numbers_and_prime_factors = {
n: [f for f in factors if divisors_by_number[f] == [1]]
for n, factors in divisors_by_number.items()
}
numbers_with_four_prime_factors = (
n
for n, prime_factors in sorted(numbers_and_prime_factors.items())
if len(prime_factors) == 4
)
answer = next(
a
for a, b, c, d in window(numbers_with_four_prime_factors, 4)
if are_consecutive(a, b, c, d)
)
print(answer)
from utils import divisors_up_to
divisors_by_number = divisors_up_to(28123)
abundant_numbers = {
n
for n, divisors in divisors_by_number.items()
if sum(divisors) > n
}
def is_sum_of_abundant_numbers(n):
return any(
(n-m) in abundant_numbers
for m in abundant_numbers
)
non_abundant_sums = (
n
for n in divisors_by_number
if not is_sum_of_abundant_numbers(n)
)
answer = sum(non_abundant_sums)
print(answer)