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PEN J Problems
21
J 21
J 21
Source:
May 25, 2007
Divisor Functions
Problem Statement
Show that for any positive integer
n
n
n
,
σ
(
n
!
)
n
!
≥
∑
k
=
1
n
1
k
.
\frac{\sigma(n!)}{n!}\ge \sum_{k=1}^{n}\frac{1}{k}.
n
!
σ
(
n
!)
≥
k
=
1
∑
n
k
1
.
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