Find the smallest whole number N such that N contains all of the digits from 0 through 9, and N
2 contains all of the digit pairs 00, 11, 22, ..., 99.
The Natural Numbers are written successively as shown below:
12345678910111213141516..........., such that the 4th digit is '4' the 9th digit is '9' but the 11th digit is '0', the 15th digit '2', the 17th '3', and so on.
What is the 40,000th digit that appears in this list ?