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Putnam
2021 Putnam
A3
A3
Part of
2021 Putnam
Problems
(1)
Putnam 2021 A3
Source:
12/5/2021
Determine all positive integers
N
N
N
for which the sphere
x
2
+
y
2
+
z
2
=
N
x^2+y^2+z^2=N
x
2
+
y
2
+
z
2
=
N
has an inscribed regular tetrahedron whose vertices have integer coordinates.
Putnam
Putnam 2021