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 A218404 #27 May 04 2025 15:13:17 %S A218404 40,224,360,2016,174592,524160,1571328,492101632,4428914688, %T A218404 83350779494400,2163091537152000,2251247910912000,2931032952207360, %U A218404 7487050986455040,155086041146982400,369127262068899840,12682035945406464000,12848564519239680000 %N A218404 Numbers k for which sigma(k)/k - 1/4 is an integer. %C A218404 a(10) > 10^11. - _Donovan Johnson_, Oct 31 2012 %C A218404 a(10) > 10^12. - _Giovanni Resta_, Nov 04 2012 %C A218404 Note that there are no terms here with abundancy 5/4. - _Michel Marcus_, Jun 26 2013 %Y A218404 Cf. A159907, A218405. %K A218404 nonn,more %O A218404 1,1 %A A218404 _Zdenek Cervenka_, Oct 28 2012 %E A218404 a(8)-a(9) from _Donovan Johnson_, Oct 31 2012 %E A218404 a(10)-a(18) from _Michel Marcus_, Jun 26 2013