This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A353765 #13 May 12 2022 16:13:29 %S A353765 1,3,5,15,27,459,819,2295,13923,69615,361179,3282147,6140043,16410735, %T A353765 30700215,99558459,277788987,497792295,1388944935 %N A353765 Numbers k for which A353749(k) is a multiple of A353749(sigma(k)), where A353749(k) = phi(k) * A064989(k), and A064989 shifts the prime factorization one step towards lower primes. %C A353765 Question: Does every term need to be odd? Could there be any other non-multiples of 3 than a(1) and a(3)? %C A353765 If it exists, a(20) > 2^32. %H A353765 <a href="/index/O#opnseqs">Index entries for sequences where odd perfect numbers must occur, if they exist at all</a> %H A353765 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A353765 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %Y A353765 Cf. A000010, A000203, A006872, A062401, A064989, A336549, A336550, A353757, A353761. %Y A353765 Positions of 1's in A353763. Cf. also A353764. %Y A353765 Conjectured to be a subsequence of A353758. %K A353765 nonn,more %O A353765 1,2 %A A353765 _Antti Karttunen_, May 10 2022