MathDB
Problems
Contests
National and Regional Contests
PEN Problems
PEN A Problems
77
77
Part of
PEN A Problems
Problems
(1)
A 77
Source:
5/25/2007
Find all positive integers, representable uniquely as
x
2
+
y
x
y
+
1
,
\frac{x^{2}+y}{xy+1},
x
y
+
1
x
2
+
y
,
where
x
x
x
and
y
y
y
are positive integers.
Divisibility Theory