Test center:

General type: the diversity of numbers.

Special topic:

Ordinary type.

Analysis:

Observe the law, all divided numbers are odd numbers, the first number is the product of the base multiplied by the previous number adjacent to the base plus 1, and the number of odd numbers is equal to the base, then find out the range of odd numbers where 20 13 is located, and the solution can be obtained.

Answer:

Solution: ∫23 = 3+5, 33 = 7+9+1,43 =13+15+17+19,

…

∴ The first number of m3 after splitting is m (m- 1)+ 1, and * * has m odd numbers.

∵45×(45- 1)+ 1= 198 1,46×(46- 1)+ 1=207 1,

∴ The 20th13rd odd number is the odd number after the cubic divisibility based on 45.

∴m=45.

So choose C.

Comments:

This question examines the changing law of numbers, and finding out the changing law of the first odd number and the split base is the key to solving the problem.