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PEN P Problems
4
4
Part of
PEN P Problems
Problems
(1)
P 4
Source:
5/25/2007
Determine all positive integers that are expressible in the form
a
2
+
b
2
+
c
2
+
c
,
a^{2}+b^{2}+c^{2}+c,
a
2
+
b
2
+
c
2
+
c
,
where
a
a
a
,
b
b
b
,
c
c
c
are integers.
Additive Number Theory