{ "id": "2212.05549", "version": "v1", "published": "2022-12-11T17:29:07.000Z", "updated": "2022-12-11T17:29:07.000Z", "title": "On a sum of a multiplicative function linked to the divisor function over the set of integers B-multiple of 5", "authors": [ "Mihoub Bouderbala" ], "comment": "7pages", "categories": [ "math.NT" ], "abstract": "Let $d(n)$ and $d^{\\ast}(n)$ be the numbers of divisors and the numbers of unitary divisors of the integer $n\\geq1$. In this paper, we prove that \\[ \\underset{n\\in\\mathcal{B}}{\\underset{n\\leq x}{\\sum}}\\frac{d(n)}{d^{\\ast}% (n)}=\\frac{16\\pi% %TCIMACRO{\\U{b2}}% %BeginExpansion {{}^2}% %EndExpansion }{123}\\underset{p}{\\prod}(1-\\frac{1}{2p% %TCIMACRO{\\U{b2}}% %BeginExpansion {{}^2}% %EndExpansion }+\\frac{1}{2p^{3}})x+\\mathcal{O}\\left( x^{\\frac{\\ln8}{\\ln10}+\\varepsilon }\\right) ,~\\left( x\\geqslant1,~\\varepsilon>0\\right) , \\] where $\\mathcal{B}$ is the set which contains any integer that is not a multiple of $5,$ but some permutations of its digits is a multiple of $5.$", "revisions": [ { "version": "v1", "updated": "2022-12-11T17:29:07.000Z" } ], "analyses": { "subjects": [ "11A25", "11N37" ], "keywords": [ "divisor function", "integers b-multiple", "multiplicative function", "unitary divisors" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }