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?
Solution
No solution yet. Write yours at
solutions/s178.md.