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 A326141 #15 Jun 19 2019 18:16:21 %S A326141 105,195,4785,22515,56865,228285,237315,484245,671853,1838145,1946955, %T A326141 3446895,4522695,12955245,37730865,52475055,53568885,87612975 %N A326141 Odd numbers n for which A318879(n) is not zero and A318879(n) divides A318878(n); odd numbers such that A326140(n) = A318879(n). %C A326141 Not a subsequence of A036798, even though many terms are members. %C A326141 Questions: Are all terms multiples of three? Multiples of 3^(2k+1) but not of 3^(2k)? Are any of the terms included in A228058, A326137? %H A326141 <a href="/index/O#opnseqs">Index entries for sequences where any odd perfect numbers must occur</a> %o A326141 (PARI) isA326141(n) = if(!(n%2),0, my(t=0, u=0); fordiv(n,d, d -= 2*eulerphi(d); if(d<0, t -= d, u += d)); (gcd(t,u)==u)); %Y A326141 Cf. A033879, A083254, A036798, A228058, A318878, A318879, A326137, A326140. %Y A326141 Cf. also A325981, A326131. %K A326141 nonn,more %O A326141 1,1 %A A326141 _Antti Karttunen_, Jun 09 2019