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Problems
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International Contests
IMO Longlists
1984 IMO Longlists
7
7
Part of
1984 IMO Longlists
Problems
(1)
C^{2n}_{n} divides lcm(1, 2, ..., 2n)
Source:
10/12/2010
Prove that for any natural number
n
n
n
, the number
(
2
n
n
)
\dbinom{2n}{n}
(
n
2
n
)
divides the least common multiple of the numbers
1
,
2
,
⋯
,
2
n
−
1
,
2
n
1, 2,\cdots, 2n -1, 2n
1
,
2
,
⋯
,
2
n
−
1
,
2
n
.
number theory
least common multiple
floor function
number theory unsolved