Does there exist a bijective map σ:N∗→N∗\sigma: \mathbb{N}^{*} \rightarrow \mathbb{N}^{*}σ:N∗→N∗ such that∑n=1∞σ(n)n2<∞?\sum_{n=1}^{\infty} \frac{\sigma(n)}{n^2}<\infty ?n=1∑∞n2σ(n)<∞? I solved itMark it doneAdd to my listKeep it in your listI like this problem3 likesLiked byAncient Tree@ancient-treeDattier@dattierUettechat@uettechatShow related problems0No related problems yet.Solutions0ReportFor an unclear, ambiguous, or possibly incorrect statement, please use the Discussion tab on the right. Report content that needs moderator intervention, such as dangerous, clearly non-mathematical, or plagiarized content.Submit