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PEN Problems
PEN P Problems
22
22
Part of
PEN P Problems
Problems
(1)
P 22
Source:
5/25/2007
Show that an integer can be expressed as the difference of two squares if and only if it is not of the form
4
k
+
2
(
k
∈
Z
)
4k+2 \; (k \in \mathbb{Z})
4
k
+
2
(
k
∈
Z
)
.
Additive Number Theory