MathDB
Problems
Contests
Undergraduate contests
Putnam
1998 Putnam
4
1998 Putnam B4
1998 Putnam B4
Source:
April 19, 2013
Putnam
floor function
college contests
Problem Statement
Find necessary and sufficient conditions on positive integers
m
m
m
and
n
n
n
so that
∑
i
=
0
m
n
−
1
(
−
1
)
⌊
i
/
m
⌋
+
⌊
i
/
n
⌋
=
0.
\sum_{i=0}^{mn-1}(-1)^{\lfloor i/m\rfloor+\lfloor i/n\rfloor}=0.
i
=
0
∑
mn
−
1
(
−
1
)
⌊
i
/
m
⌋
+
⌊
i
/
n
⌋
=
0.
Back to Problems
View on AoPS