def eul55():
"""How many Lychrel numbers are there below n = ten-thousand?"""
lycs = []
for num in range(1, 10000):
i = num
found, itr = False, 0
while not found and itr < 50:
i += eul.reverse_digits(i)
found = eul.palindrome(i)
itr += 1
if not found:
lycs.append(num)
return len(lycs)
def eul4(n):
"""Find the largest palindrome made from the product of two n=3-digit numbers."""
return max([x * y for x in range(10 ** (n - 1), 10 ** n) for y in
range(10 ** (n - 1), 10 ** n) if eul.palindrome(x * y)])
def eul36():
"""Find the sum of all numbers, less than n = one million, which are palindromic in base 10 and base 2."""
return sum([x for x in range(1, 1000001) if eul.palindrome(x) and eul.palindrome(str(bin(x))[2:])])
def eul4():
"""Find the largest palindrome made from the product of two 3-digit numbers."""
return max([x * y for x in range(100, 1000) for y in range(100, 1000) if eul.palindrome(x * y)])