Zhi-Wei Sun

collaborators

2 papers

math.NT2026

Universal sums via products of Ramanujan's theta functions

Nasser Abdo Saeed Bulkhali, Zhi-Wei Sun

An integer-valued polynomial $P (x, y, z)$ is said to be universal (over $Z$ ) if each nonnegative integer can be written as $P (x, y, z)$ with $x, y, z \in Z$ . In this paper,…

math.NT2024

New results similar to Lagrange's four-square theorem

Zhi-Wei Sun

In this paper we establish some new results similar to Lagrange's four-square theorem. For example, we prove that any integer $n > 1$ can be written as $w(5w+1)/2+x(5x+1)/2+y(5y+1)/2…