bancaldo™

Take the number 192 and multiply it by each of 1, 2, and 3:
    192 × 1 = 192
    192 × 2 = 384
    192 × 3 = 576
By concatenating each product we get the 1 to 9 pandigital, 192384576.
We will call 192384576 the concatenated product of 192 and (1,2,3)
The same can be achieved by starting with 9 and multiplying by 1, 2, 3, 4, and 5,
giving the pandigital, 918273645, which is the concatenated product of 9 and (1,2,3,4,5).
What is the largest 1 to 9 pandigital 9-digit number that can be formed as the
concatenated product of an integer with (1,2, ... , n) where n > 1?

python:

import time
ts = time.time()

def is_pandigital(n):
    digits = range(1,10)
    num = [int(n) for n in str(n)]
    num.sort()
    return num == digits

panmax = 123456789 # min 1-9 pandigital
for n in xrange(1, 10000):
    res = ''
    for m in xrange(1, 10):
        res += str(n * m)
        if len(res) == 9 and is_pandigital(res):
            if int(res) > panmax:
                panmax = int(res)

print panmax
print time.time() - ts