def test_is_amicable_number(self):
self.assertEqual(mathhelper.is_amicable(-1), False)
self.assertEqual(mathhelper.is_amicable(0), False)
self.assertEqual(mathhelper.is_amicable(1), False)
self.assertEqual(mathhelper.is_amicable(11), False)
self.assertEqual(mathhelper.is_amicable(13), False)
self.assertEqual(mathhelper.is_amicable(220), True)
self.assertEqual(mathhelper.is_amicable(284), True)
self.assertEqual(mathhelper.is_amicable(1100), False)
self.assertEqual(mathhelper.is_amicable(1184), True)
def problem21():
""" Amicable numbers
Evaluate the sum of all the amicable numbers under 10000.
"""
return sum(x for x in range(1, 10000) if mathhelper.is_amicable(x))
