def double_base_palindromes(max_n):
""" Return a list of all decimal-binary palindromes up to max_n."""
palindromes = []
for n in range(1, max_n + 1, 2): # binary palindromes must be odd
if common.is_str_palindrome(str(n)) and common.is_str_palindrome(bin(n)[2:]):
palindromes.append(n)
return palindromes
def is_num_palindrome(n):
if n < 10:
return True
else:
return common.is_str_palindrome(str(n))
