https://plus.google.com/u/0/114070220225686847236/posts/d7xrq9ph7WJ There are no repeated digits, and no adjacent digits with a difference of one, in the number 13524. How many such arrangements of 5 digits are there? What's the shortest program you can write to find out?

nonrepeating_digits.py

#!/usr/bin/python

# https://plus.google.com/u/0/114070220225686847236/posts/d7xrq9ph7WJ

# There are no repeated digits, and no adjacent digits with a
# difference of one, in the number 13524.  How many such arrangements
# of 5 digits are there?  What's the shortest program you can write to
# find out?

import itertools

print sum(s[0] and all(abs(s[i] - s[i+1]) - 1
                       for i in range(4))
          for s in itertools.permutations(range(10), 5))

Shorten this by changing map(int, '0123456789') to range(10).