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Putnam
1975 Putnam
A1
Putnam 1975 A1
Putnam 1975 A1
Source: Putnam 1975
February 17, 2022
Putnam
number theory
Problem Statement
Show that a positive integer
m
m
m
is a sum of two triangular numbers if and only if
4
m
+
1
4m+1
4
m
+
1
is a sum of two squares.
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