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Contests
National and Regional Contests
PEN Problems
PEN A Problems
47
47
Part of
PEN A Problems
Problems
(1)
A 47
Source:
5/25/2007
Let
n
n
n
be a positive integer with
n
>
1
n>1
n
>
1
. Prove that
1
2
+
⋯
+
1
n
\frac{1}{2}+\cdots+\frac{1}{n}
2
1
+
⋯
+
n
1
is not an integer.
factorial
floor function
number theory
prime numbers
Divisibility Theory