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15
Minimum of sum or difference of fifth powers
Minimum of sum or difference of fifth powers
Source:
October 9, 2010
number theory unsolved
number theory
Problem Statement
Consider all the sums of the form
∑
k
=
1
1985
e
k
k
5
=
±
1
5
±
2
5
±
⋯
±
198
5
5
\displaystyle\sum_{k=1}^{1985} e_kk^5=\pm 1^5\pm 2^5\pm\cdots\pm1985^5
k
=
1
∑
1985
e
k
k
5
=
±
1
5
±
2
5
±
⋯
±
198
5
5
where
e
k
=
±
1
e_k=\pm 1
e
k
=
±
1
. What is the smallest nonnegative value attained by a sum of this type?
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