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 A218408 #19 May 13 2023 17:13:02 %S A218408 15,90,3360,2618880,5059200,4873497600,7381524480,27990144000, %T A218408 57846297600,4609292688000,4440104532864000,106644933787392000, %U A218408 164741543366400000,454310107592140800,1084892424295680000,1160492902900531200,10932800808939609600 %N A218408 Numbers k for which sigma(k)/k - 3/5 is an integer. %C A218408 a(10) > 10^11. - _Donovan Johnson_, Oct 31 2012 %C A218408 a(10) > 10^12. - _Giovanni Resta_, Nov 04 2012 %Y A218408 Cf. A218406, A218407, A218427. %K A218408 nonn %O A218408 1,1 %A A218408 _Zdenek Cervenka_, Oct 28 2012 %E A218408 a(6)-a(9) from _Donovan Johnson_, Oct 31 2012 %E A218408 More terms from _Michel Marcus_, Jun 26 2013