{"title":"某些交替数列的非理性指数","authors":"Iekata Shiokawa","doi":"10.1007/s11139-024-00923-5","DOIUrl":null,"url":null,"abstract":"<p>Let <i>m</i> be a positive integer, <span>\\((w_n)\\)</span> be a sequence of positive integers, and <span>\\((y_n)\\)</span> be a sequence of nonzero integers with <span>\\(y_1\\ge 1\\)</span>. Define <span>\\(q_0=1, q_1=w_0, q_{n+1}=q_{n-1}(w_nq_n^m+y_n) \\,\\,(n\\ge 1)\\)</span>. Under certain assumptions on <span>\\((w_n)\\)</span> and <span>\\((y_n)\\)</span>, we give the exact value of the irrationality exponent of the number </p><span>$$\\begin{aligned} \\xi =\\sum _{n=1}^{\\infty }(-1)^{n-1}\\frac{y_1y_2\\cdots y_n}{q_nq_{n-1}}. \\end{aligned}$$</span>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"107 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Irrationality exponents of certain alternating series\",\"authors\":\"Iekata Shiokawa\",\"doi\":\"10.1007/s11139-024-00923-5\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Let <i>m</i> be a positive integer, <span>\\\\((w_n)\\\\)</span> be a sequence of positive integers, and <span>\\\\((y_n)\\\\)</span> be a sequence of nonzero integers with <span>\\\\(y_1\\\\ge 1\\\\)</span>. Define <span>\\\\(q_0=1, q_1=w_0, q_{n+1}=q_{n-1}(w_nq_n^m+y_n) \\\\,\\\\,(n\\\\ge 1)\\\\)</span>. Under certain assumptions on <span>\\\\((w_n)\\\\)</span> and <span>\\\\((y_n)\\\\)</span>, we give the exact value of the irrationality exponent of the number </p><span>$$\\\\begin{aligned} \\\\xi =\\\\sum _{n=1}^{\\\\infty }(-1)^{n-1}\\\\frac{y_1y_2\\\\cdots y_n}{q_nq_{n-1}}. \\\\end{aligned}$$</span>\",\"PeriodicalId\":501430,\"journal\":{\"name\":\"The Ramanujan Journal\",\"volume\":\"107 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Ramanujan Journal\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1007/s11139-024-00923-5\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Ramanujan Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s11139-024-00923-5","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Irrationality exponents of certain alternating series
Let m be a positive integer, \((w_n)\) be a sequence of positive integers, and \((y_n)\) be a sequence of nonzero integers with \(y_1\ge 1\). Define \(q_0=1, q_1=w_0, q_{n+1}=q_{n-1}(w_nq_n^m+y_n) \,\,(n\ge 1)\). Under certain assumptions on \((w_n)\) and \((y_n)\), we give the exact value of the irrationality exponent of the number