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 A218415 #19 May 13 2023 17:31:05 %S A218415 9,1782,2160,5400,13104,52141320,117641160,173365920,6829038720, %T A218415 12415092480,13356796320,104381747712,513480135168,1377031864320, %U A218415 6578372828160,26896578508800,294208373809152,1447285170659328,3151812152130048,7734746166732288 %N A218415 Numbers k for which sigma(k)/k - 4/9 is an integer. %C A218415 a(12) > 10^11. - _Donovan Johnson_, Nov 01 2012 %C A218415 a(14) > 10^12. - _Giovanni Resta_, Nov 04 2012 %Y A218415 Cf. A218414, A218430, A160320, A218416, A160321, A218417, A218418. %K A218415 nonn %O A218415 1,1 %A A218415 _Zdenek Cervenka_, Oct 28 2012 %E A218415 a(6)-a(11) from _Donovan Johnson_, Nov 01 2012 %E A218415 a(12)-a(13) from _Giovanni Resta_, Nov 04 2012 %E A218415 More terms from _Michel Marcus_, Jun 25 2013