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National and Regional Contests
PEN Problems
PEN A Problems
48
48
Part of
PEN A Problems
Problems
(1)
A 48
Source:
5/25/2007
Let
n
n
n
be a positive integer. Prove that
1
3
+
⋯
+
1
2
n
+
1
\frac{1}{3}+\cdots+\frac{1}{2n+1}
3
1
+
⋯
+
2
n
+
1
1
is not an integer.
Divisibility Theory
pen