MathDB
Problems
Contests
National and Regional Contests
China Contests
XES Mathematics Olympiad
the 11th XMO
3
3
Part of
the 11th XMO
Problems
(1)
Another standard NT Cookie
Source: 11th XMO #3
2/13/2023
Let
p
p
p
is a prime and
p
≡
2
(
m
o
d
3
)
p\equiv 2\pmod 3
p
≡
2
(
mod
3
)
. For
∀
a
∈
Z
\forall a\in\mathbb Z
∀
a
∈
Z
, if
p
∣
∏
i
=
1
p
(
i
3
−
a
i
−
1
)
,
p\mid \prod\limits_{i=1}^p(i^3-ai-1),
p
∣
i
=
1
∏
p
(
i
3
−
ai
−
1
)
,
then
a
a
a
is called a "GuGu" number. How many "GuGu" numbers are there in the set
{
1
,
2
,
⋯
,
p
}
?
\{1,2,\cdots ,p\}?
{
1
,
2
,
⋯
,
p
}?
(We are allowed to discuss now. It is after 00:00 Feb 14 Beijing Time)
prime numbers
number theory