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

## Main Article Content

## 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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## References

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