MathDB
Problems
Contests
National and Regional Contests
Iran Contests
Pre-Preparation Course Examination
2007 Pre-Preparation Course Examination
15
15
Part of
2007 Pre-Preparation Course Examination
Problems
(1)
Existing a subset of N-Iran 3rd round-Number Theory 2007
Source:
7/28/2010
Does there exists a subset of positive integers with infinite members such that for every two members
a
,
b
a,b
a
,
b
of this set
a
2
−
a
b
+
b
2
∣
(
a
b
)
2
a^2-ab+b^2|(ab)^2
a
2
−
ab
+
b
2
∣
(
ab
)
2
number theory unsolved
number theory