Czechoslovak Mathematical Journal, Vol. 73, No. 1, pp. 297-310, 2023
Consecutive square-free values of the type $x^2+y^2+z^2+k$, $x^2+y^2+z^2+k+1$
Ya-Fang Feng
Received April 8, 2022. Published online November 15, 2022.
Abstract: We show that for any given integer $k$ there exist infinitely many consecutive square-free numbers of the type $x^2+y^2+z^2+k$, $x^2+y^2+z^2+k+1$. We also establish an asymptotic formula for $1\leq x, y, z \leq H$ such that $x^2+y^2+z^2+k$, $x^2+y^2+z^2+k+1$ are square-free. The method we used in this paper is due to Tolev.
Keywords: square-free number; Salié sum; Gauss sum
Affiliations: Ya-Fang Feng, School of Mathematical Sciences, Nanjing Normal University, No. 22, Hankou Road, Nanjing 210023, P. R. China, e-mail: yafangf@126.com