MathDB
Problems
Contests
National and Regional Contests
PEN Problems
PEN A Problems
20
A 20
A 20
Source:
May 25, 2007
induction
abstract algebra
modular arithmetic
quadratics
number theory
Divisibility Theory
Problem Statement
Determine all positive integers
n
n
n
for which there exists an integer
m
m
m
such that
2
n
ā
1
2^{n}-1
2
n
ā
1
divides
m
2
+
9
m^{2}+9
m
2
+
9
.
Back to Problems
View on AoPS