Korean J. Math. Vol. 31 No. 2 (2023) pp.181-188
DOI: https://doi.org/10.11568/kjm.2023.31.2.181

A simple proof for Ji-Kim-Oh's theorem

Main Article Content

Byeong Moon Kim
Ji Young Kim

Abstract

In 1911, Dubouis determined all positive integers represented by sums of $k$ nonvanishing squares for all $k \geq 4$. As a generalization, Y.-S. Ji, M.-H. Kim and B.-K. Oh determined all positive definite binary quadratic forms represented by sums of $k$ nonvanishing squares for all $k \geq 5$. In this article, we give a simple proof for Ji-Kim-Oh's theorem for all $k \geq 10$.



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Supporting Agencies

National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2018R1D1A3B07048195, NRF-2020R1I1A1A01053318)

References

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