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 A334128 #7 May 17 2020 03:34:41 %S A334128 135,1365,42819777 %N A334128 Integers m such that sigma(m) + sigma(7*m) = 16*m. %C A334128 This is the case h = 7 of the h-perfect numbers as defined in the Harborth link. %C A334128 If gcd(m, 7) = 1 and m is even, then m must be of the form 2*q, where 27*sigma(q) = 32*q and gcd(q, 7) = 1. %C A334128 a(4) > 3.5*10^12, if it exists. - _Giovanni Resta_, May 17 2020 %H A334128 Heiko Harborth, <a href="http://ami.ektf.hu/uploads/papers/finalpdf/AMI_41_from57to62.pdf">On h-perfect numbers</a>, Annales Mathematicae et Informaticae, 41 (2013) pp. 57-62. %o A334128 (PARI) isok(m) = sigma(m) + sigma(7*m) == 16*m; %Y A334128 Cf. A000203, A000396, A281993, A330412, A330413. %K A334128 nonn,bref,hard,more %O A334128 1,1 %A A334128 _Jinyuan Wang_, May 15 2020