The number, 1406357289, is a 0 to 9 pandigital number because it is made up of each of the digits 0 to 9 in some order, but it also has a rather interesting sub-string divisibility property.
Let d1 be the 1st digit, d2 be the 2nd digit, and so on. In this way, we note the following:
d2d3d4=406 is divisible by 2
d3d4d5=063 is divisible by 3
d4d5d6=635 is divisible by 5
d5d6d7=357 is divisible by 7
d6d7d8=572 is divisible by 11
d7d8d9=728 is divisible by 13
d8d9d10=289 is divisible by 17
Find the sum of all 0 to 9 pandigital numbers with this property.
In [1]:
def has_property(s):
p = [2,3,5,7,11,13,17]
for i in range(2,9):
if int(s[i-1: i+2]) % p[i-2] != 0:
return False
return True
assert has_property('1406357289')
import itertools
pandigitals = []
for s in itertools.permutations([str(i) for i in range(10)]):
n = ''.join(s)
if has_property(n):
pandigitals.append(int(n))
print pandigitals
print sum(pandigitals)
In [ ]: