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 A218411 #14 May 13 2023 20:00:19 %S A218411 280,18620,411264,804384,871416,1222144,1284192,164989440,270138960, %T A218411 318729600,326781000,396168192,481572000,623397600,675347400, %U A218411 995248800,3444711424,4426793280,307030348800,465036042240,880719036120 %N A218411 Numbers k for which sigma(k)/k - 4/7 is an integer. %C A218411 a(19) > 10^11. - _Donovan Johnson_, Oct 31 2012 %C A218411 a(22) > 10^12. - _Giovanni Resta_, Nov 04 2012 %Y A218411 Cf. A218428, A218409, A218410, A218412, A218413. %K A218411 nonn %O A218411 1,1 %A A218411 _Zdenek Cervenka_, Oct 28 2012 %E A218411 a(8)-a(18) from _Donovan Johnson_, Oct 31 2012 %E A218411 a(19)-a(21) from _Giovanni Resta_, Nov 04 2012