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Putnam
1967 Putnam
B5
Putnam 1967 B5
Putnam 1967 B5
Source: Putnam 1967
May 14, 2022
Putnam
Binomial
expansion
Problem Statement
Show that the sum of the first
n
n
n
terms in the binomial expansion of
(
2
−
1
)
−
n
(2-1)^{-n}
(
2
−
1
)
−
n
is
1
2
,
\frac{1}{2},
2
1
,
where
n
n
n
is a positive integer.
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