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Baltic Way
2020 Baltic Way
19
19
Part of
2020 Baltic Way
Problems
(1)
A rounded multiple of the divisor function divides the number itself
Source: Baltic Way 2020, Problem 19
11/14/2020
Denote by
d
(
n
)
d(n)
d
(
n
)
the number of positive divisors of a positive integer
n
n
n
. Prove that there are infinitely many positive integers
n
n
n
such that
⌊
3
⋅
d
(
n
)
⌋
\left\lfloor\sqrt{3}\cdot d(n)\right\rfloor
⌊
3
⋅
d
(
n
)
⌋
divides
n
n
n
.
number theory
number theory proposed
divisor function