Let denote the number of representations of the positive integer as the sum of two squares and three biquadrates of primes and we write for the number of positive integers satisfying , and
where is the singular series. In this paper, we prove
for any . This result constitutes a refinement upon that of Friedlander and Wooley (2014).
"Waring–Goldbach problem: two squares and three biquadrates." Rocky Mountain J. Math. 50 (1) 355 - 367, Febuary 2020. https://doi.org/10.1216/rmj.2020.50.355