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Putnam
1988 Putnam
B4
Putnam 1988 B4
Putnam 1988 B4
Source:
August 6, 2019
Putnam
Convergence
Problem Statement
Prove that if
∑
n
=
1
∞
a
n
\sum_{n=1}^\infty a_n
∑
n
=
1
∞
a
n
is a convergent series of positive real numbers, then so is
∑
n
=
1
∞
(
a
n
)
n
/
(
n
+
1
)
\sum_{n=1}^\infty (a_n)^{n/(n+1)}
∑
n
=
1
∞
(
a
n
)
n
/
(
n
+
1
)
.
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