关于 20 岁之友的说明

Tapas Chatterjee, Sagar Mandal, Sourav Mandal
{"title":"关于 20 岁之友的说明","authors":"Tapas Chatterjee, Sagar Mandal, Sourav Mandal","doi":"arxiv-2409.04451","DOIUrl":null,"url":null,"abstract":"Does $20$ have a friend? Or is it a solitary number? A folklore conjecture\nasserts that $20$ has no friends i.e. it is a solitary number. In this article,\nwe prove that, a friend $N$ of $20$ is of the form $N=2\\cdot5^{2a}m^2$ and it\nhas atleast six distinct prime divisors. Also we prove that $N$ must be atleast\n$2\\cdot 10^{12}$. Furthermore, we show that $\\Omega(N)\\geq 2\\omega(N)+6a-5$ and\nif $\\Omega(m)\\leq K$ then $N< 10\\cdot 6^{(2^{K-2a+3}-1)^2}$, where $\\Omega(n)$\nand $\\omega(n)$ denote the total number of prime divisors and the number of\ndistinct prime divisors of the integer $n$ respectively. In addition, we deduce\nthat, not all exponents of odd prime divisors of friend $N$ of $20$ are\ncongruent to $-1$ modulo $f$, where $f$ is the order of $5$ in\n$(\\mathbb{Z}/p\\mathbb{Z})^\\times$ such that $3\\mid f$ and $p$ is a prime\ncongruent to $1$ modulo $6$.","PeriodicalId":501502,"journal":{"name":"arXiv - MATH - General Mathematics","volume":"36 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A note on friends of 20\",\"authors\":\"Tapas Chatterjee, Sagar Mandal, Sourav Mandal\",\"doi\":\"arxiv-2409.04451\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Does $20$ have a friend? Or is it a solitary number? A folklore conjecture\\nasserts that $20$ has no friends i.e. it is a solitary number. In this article,\\nwe prove that, a friend $N$ of $20$ is of the form $N=2\\\\cdot5^{2a}m^2$ and it\\nhas atleast six distinct prime divisors. Also we prove that $N$ must be atleast\\n$2\\\\cdot 10^{12}$. Furthermore, we show that $\\\\Omega(N)\\\\geq 2\\\\omega(N)+6a-5$ and\\nif $\\\\Omega(m)\\\\leq K$ then $N< 10\\\\cdot 6^{(2^{K-2a+3}-1)^2}$, where $\\\\Omega(n)$\\nand $\\\\omega(n)$ denote the total number of prime divisors and the number of\\ndistinct prime divisors of the integer $n$ respectively. In addition, we deduce\\nthat, not all exponents of odd prime divisors of friend $N$ of $20$ are\\ncongruent to $-1$ modulo $f$, where $f$ is the order of $5$ in\\n$(\\\\mathbb{Z}/p\\\\mathbb{Z})^\\\\times$ such that $3\\\\mid f$ and $p$ is a prime\\ncongruent to $1$ modulo $6$.\",\"PeriodicalId\":501502,\"journal\":{\"name\":\"arXiv - MATH - General Mathematics\",\"volume\":\"36 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - General Mathematics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.04451\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - General Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.04451","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

摘要

20 美元有朋友吗?或者它是一个孤独的数字?一个民间猜想认为 $20$ 没有朋友,即它是一个孤数。在本文中,我们证明 $20$ 的朋友 $N$ 是 $N=2\cdot5^{2a}m^2$ 的形式,并且至少有六个不同的素除。同时我们证明 $N$ 必须至少是 $2\cdot10^{12}$。此外,我们还证明了 $\Omega(N)/geq 2\omega(N)+6a-5$ 并且如果 $\Omega(m)/leq K$ 那么 $N< 10\cdot 6^{(2^{K-2a+3}-1)^2}$ 其中 $\Omega(n)$ 和 $\omega(n)$ 分别表示整数 $n$ 的素除数总数和不同素除数的个数。此外,我们还推导出,并不是所有 $20$ 的朋友 $N$ 的奇素数除数的指数都与 $-1$ 相等,这里的 $f$ 是$(\mathbb{Z}/p\mathbb{Z})^\times$中$5$的阶,使得$3\mid f$ 和 $p$ 是与 $1$ 相等的初等数,模为 $6$。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
A note on friends of 20
Does $20$ have a friend? Or is it a solitary number? A folklore conjecture asserts that $20$ has no friends i.e. it is a solitary number. In this article, we prove that, a friend $N$ of $20$ is of the form $N=2\cdot5^{2a}m^2$ and it has atleast six distinct prime divisors. Also we prove that $N$ must be atleast $2\cdot 10^{12}$. Furthermore, we show that $\Omega(N)\geq 2\omega(N)+6a-5$ and if $\Omega(m)\leq K$ then $N< 10\cdot 6^{(2^{K-2a+3}-1)^2}$, where $\Omega(n)$ and $\omega(n)$ denote the total number of prime divisors and the number of distinct prime divisors of the integer $n$ respectively. In addition, we deduce that, not all exponents of odd prime divisors of friend $N$ of $20$ are congruent to $-1$ modulo $f$, where $f$ is the order of $5$ in $(\mathbb{Z}/p\mathbb{Z})^\times$ such that $3\mid f$ and $p$ is a prime congruent to $1$ modulo $6$.
求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信