{ "id": "2505.01645", "version": "v1", "published": "2025-05-03T01:19:00.000Z", "updated": "2025-05-03T01:19:00.000Z", "title": "Note on a sum involving the divisor function", "authors": [ "Liuying Wu" ], "categories": [ "math.NT" ], "abstract": "Let $d(n)$ be the divisor function and denote by $[t]$ the integral part of the real number $t$. In this paper, we prove that $$\\sum_{n\\leq x^{1/c}}d\\left(\\left[\\frac{x}{n^c}\\right]\\right)=d_cx^{1/c}+\\mathcal{O}_{\\varepsilon,c} \\left(x^{\\max\\{(2c+2)/(2c^2+5c+2),5/(5c+6)\\}+\\varepsilon}\\right),$$ where $d_c=\\sum_{k\\geq1}d(k)\\left(\\frac{1}{k^{1/c}}-\\frac{1}{(k+1)^{1/c}}\\right)$ is a constant. This result constitutes an improvement upon that of Feng.", "revisions": [ { "version": "v1", "updated": "2025-05-03T01:19:00.000Z" } ], "analyses": { "keywords": [ "divisor function", "integral part", "real number", "result constitutes" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }