## Step Numbers

### Problem 178

Consider the number 45656.

It can be seen that each pair of consecutive digits of 45656 has a difference of one.

A number for which every pair of consecutive digits has a difference of one is called a step number.

A pandigital number contains every decimal digit from 0 to 9 at least once.

How many pandigital step numbers less than 10

It can be seen that each pair of consecutive digits of 45656 has a difference of one.

A number for which every pair of consecutive digits has a difference of one is called a step number.

A pandigital number contains every decimal digit from 0 to 9 at least once.

How many pandigital step numbers less than 10

^{40}are there?