Problem 495
Writing n as the product of k distinct positive integers
Let W(n,k) be the number of ways in which n can be written as the product of k distinct positive integers.
For example, W(144,4) = 7. There are 7 ways in which 144 can be written as a product of 4 distinct positive integers:
- 144 = 1×2×4×18
- 144 = 1×2×8×9
- 144 = 1×2×3×24
- 144 = 1×2×6×12
- 144 = 1×3×4×12
- 144 = 1×3×6×8
- 144 = 2×3×4×6
Note that permutations of the integers themselves are not considered distinct.
Furthermore, W(100!,10) modulo 1 000 000 007 = 287549200.
Find W(10000!,30) modulo 1 000 000 007.
将n拆分成k个不重复正整数的乘积
用W(n,k)表示将n拆分成k个不重复正整数的乘积的方法数。
例如,W(144,4) = 7,即有7种方法将144拆分成4个不重复正整数的乘积:
- 144 = 1×2×4×18
- 144 = 1×2×8×9
- 144 = 1×2×3×24
- 144 = 1×2×6×12
- 144 = 1×3×4×12
- 144 = 1×3×6×8
- 144 = 2×3×4×6
注意正整数的不同排列不视为不同的拆分方法。
进一步的,我们有W(100!,10)除以1 000 000 007的余数为287549200。
求W(10000!,30)除以1 000 000 007的余数。