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International Contests
International Olympiad of Metropolises
2018 IOM
4
4
Part of
2018 IOM
Problems
(1)
Consecutive divisors two apart
Source: IOM 2018 #4, Ivan Mitrofanov
9/6/2018
Let
1
=
d
0
<
d
1
<
⋯
<
d
m
=
4
k
1 = d_0 < d_1 < \dots < d_m = 4k
1
=
d
0
<
d
1
<
⋯
<
d
m
=
4
k
be all positive divisors of
4
k
4k
4
k
, where
k
k
k
is a positive integer. Prove that there exists
i
∈
{
1
,
…
,
m
}
i \in \{1, \dots, m\}
i
∈
{
1
,
…
,
m
}
such that
d
i
−
d
i
−
1
=
2
d_i - d_{i-1} = 2
d
i
−
d
i
−
1
=
2
.Ivan Mitrofanov
number theory
IOM