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 A227305 #12 Jul 13 2013 11:50:12 %S A227305 2,3,5,6,10,19,52,118,1054,3201,8586,9802,16120,60556,140698,145216, %T A227305 11273536,29886160,44868748,8748377956,325377469696,2368739714188 %N A227305 Numbers n such that sigma(n) - sigma(n-1) divides n. %C A227305 a(23) > 2.5*10^12. - _Giovanni Resta_, Jul 13 2013 %Y A227305 Cf. A053222, A067816, A223138, A225211. %K A227305 nonn,more %O A227305 1,1 %A A227305 _Alex Ratushnyak_, Jul 05 2013 %E A227305 a(21)-a(22) from _Giovanni Resta_, Jul 13 2013