MathDB
Problems
Contests
National and Regional Contests
Turkey Contests
Turkey Team Selection Test
2021 Turkey Team Selection Test
1
3^n+47 cannot divide 20x5^n-2
3^n+47 cannot divide 20x5^n-2
Source: Turkey TST 2021 P1 Day 1
May 19, 2021
legendre symbol
prime numbers
Divisibility
number theory
Problem Statement
Let
n
n
n
be a positive integer. Prove that
20
⋅
5
n
−
2
3
n
+
47
\frac{20 \cdot 5^n-2}{3^n+47}
3
n
+
47
20
⋅
5
n
−
2
is not an integer.
Back to Problems
View on AoPS