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 A218406 #26 May 13 2023 20:00:49 %S A218406 5,420,7440,8190,18600,121920,131040,95472000,102136320,197308800, %T A218406 433305600,503255040,71271827200,91967616000,128848035840, %U A218406 190066406400,287879454720,354560976000,799959888000,2061580369920,2208930048000,100368143884800,341546502528000 %N A218406 Numbers k for which sigma(k)/k - 1/5 is an integer. %C A218406 a(15) > 10^11. - _Donovan Johnson_, Oct 31 2012 %C A218406 a(20) > 10^12. - _Giovanni Resta_, Nov 04 2012 %C A218406 Note that there are no terms here with abundancy 11/5 (k=2). - _Michel Marcus_, Jun 26 2013 %Y A218406 Cf. A218407, A218408, A218427. %K A218406 nonn %O A218406 1,1 %A A218406 _Zdenek Cervenka_, Oct 28 2012 %E A218406 a(8)-a(14) from _Donovan Johnson_, Oct 31 2012 %E A218406 a(15)-a(19) from _Giovanni Resta_, Nov 04 2012 %E A218406 More terms from _Michel Marcus_, Jun 26 2013