Let $ d_3(n) $ denote the 3-th divisor function. In this paper, we study the asymptotic formula of the sum
$ \sum\limits_{\substack{1 \leqslant n_1,n_2 \leqslant X^{\frac{1}{2}} \\ 1 \leqslant n_3 \leqslant X^{\frac{1}{k}}}} d_3(n_1^2+n_2^2+n_3^k) $
with $ n_1, n_2, n_3\in \mathbb{Z}^+ $ and $ k \geqslant 3 $ be an integer. Previously only the case of $ k=2 $ is studied.
Citation: Li Zhou, Liqun Hu. Sum of the triple divisor function of mixed powers[J]. AIMS Mathematics, 2022, 7(7): 12885-12896. doi: 10.3934/math.2022713
Let $ d_3(n) $ denote the 3-th divisor function. In this paper, we study the asymptotic formula of the sum
$ \sum\limits_{\substack{1 \leqslant n_1,n_2 \leqslant X^{\frac{1}{2}} \\ 1 \leqslant n_3 \leqslant X^{\frac{1}{k}}}} d_3(n_1^2+n_2^2+n_3^k) $
with $ n_1, n_2, n_3\in \mathbb{Z}^+ $ and $ k \geqslant 3 $ be an integer. Previously only the case of $ k=2 $ is studied.
[1] | C. E. Chace, The divisor problem for arithmetic progressions with small modulus, Acta Arith., 61 (1992), 35–50. |
[2] | C. E. Chace, Writing integers as sums of products, Trans. Am. Math. Soc., 345 (1994), 367–379. https://doi.org/10.1090/S0002-9947-1994-1257641-3 doi: 10.1090/S0002-9947-1994-1257641-3 |
[3] | R. T. Guo, W. G. Zhai, Some problems about the ternary quadratic form $m_1^2 +m_2^2 +m_3^2$, Acta Arith., bf 156 (2012), 101–121. |
[4] | L. Q. Hu, An asymptotic formula related to the divisors of the quaternary quadratic form, Acta Arith., 166 (2014), 129–140. https://doi.org/10.4064/aa166-2-2 doi: 10.4064/aa166-2-2 |
[5] | L. Q. Hu and L. Yang, Sums of the triple divisor function over values of a quaternary quadratic form, Acta Arith., 183 (2018), 63–85. https://doi.org/10.4064/aa170120-20-10 doi: 10.4064/aa170120-20-10 |
[6] | L. K. Hua, Introduction to Number Theory, Science Press, Beijing, 1957 (in Chinese). |
[7] | X. D. Lü, Q. W. Mu, The Sum of Divisors of Mixed Powers, Advances in Mathematics (in China), 45 (2016), 357–364. |
[8] | Q. F. Sun, D. Y. Zhang, Sums of the triple divisor function over values of a ternary quadratic form, J. Number Theory, 168 (2016), 215–246. |
[9] | R. C. Vaughan, The Hardy-Littlewood Method, 2nd ed., Cambridge Tracts in Math., vol. 125, Cambridge University, Cambridge, 1997. |
[10] | L. L. Zhao, The sum of divisors of a quadratic form, Acta Arith., 163 (2014), 161–177. https://doi.org/10.4064/aa163-2-6 doi: 10.4064/aa163-2-6 |