def is_strong_harshad(n):
""" Determine if n / (sum of digits of n) is prime
:param n:
:return:
"""
sum_digits = euler.sum_digits(n)
return n % sum_digits == 0 and euler.is_prime(n / sum_digits)
def solve(max_value):
strong_right_truncatable_harshad_primes = []
for right_truncatable in right_truncatable_generator():
# for each right truncatable number, figure out if it is strong,
# prime. If so add to sum
if is_strong_harshad(right_truncatable):
for new_digit in xrange(10):
to_test = right_truncatable * 10 + new_digit
if euler.is_prime(to_test):
strong_right_truncatable_harshad_primes.append(to_test)
if to_test > max_value:
return sum(strong_right_truncatable_harshad_primes)
return sum(strong_right_truncatable_harshad_primes)