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 A218427 #26 Apr 23 2023 02:21:36 %S A218427 10,60,1170,114660,72602880,668304000,714954240,1307124000,1381161600, %T A218427 2701389600,8052817920,10181689600,643773312000,1330464844800, %U A218427 2015156183040,3522876144480,15462510336000,23885971200000,702577007193600,908714417345280 %N A218427 Numbers k for which sigma(k)/k - 4/5 is an integer. %C A218427 a(13) > 10^11. - _Donovan Johnson_, Oct 31 2012 %C A218427 a(14) > 10^12. - _Giovanni Resta_, Nov 04 2012 %H A218427 M. Drennen, T. Gunter, P. Johnson and J. Ward, <a href="http://web2.clarkson.edu/projects/cosi/fa2006/students/wardjm/lonenumber.pdf">The Loneliest Number</a> %H A218427 Jeffrey Ward, <a href="http://arxiv.org/abs/0806.1001">Does Ten Have a Friend?</a>, arXiv:0806.1001 [math.NT], 2008. %Y A218427 Cf. A218406, A218407, A218408. %K A218427 nonn %O A218427 1,1 %A A218427 _Zdenek Cervenka_, Oct 28 2012 %E A218427 a(5)-a(12) from _Donovan Johnson_, Oct 31 2012 %E A218427 a(13) from _Giovanni Resta_, Nov 04 2012 %E A218427 More terms from _Michel Marcus_, Jun 26 2013