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 A168127 #16 Feb 22 2020 08:30:58
%S A168127 1,3,29,365,1225,81595,86249,185699,582917,11413204,16646745763,
%T A168127 311408527843,709342670921,881267828693
%N A168127 Numbers k such that Sum_{j=1..k} sigma(j) / sigma(k) is an integer.
%C A168127 Numbers k such that A024916(k)/A000203(k) is an integer.
%C A168127 Corresponding values of sigma(k), Sum_{j=1..k} sigma(j) and Sum_{j=1..k} sigma(j)/sigma(k) are given in A168129, A168130 and A168128. - _Jaroslav Krizek_, Nov 21 2009
%C A168127 a(11) > 10^10. - _Donovan Johnson_, Oct 16 2013
%C A168127 a(15) > 10^12. - _Giovanni Resta_, Jun 06 2016
%e A168127 29 is in the sequence because A024916(29) / A000203(29) = 690 / 30 = 23 is an integer.
%o A168127 (PARI) m=0; for(k=1, 11413204, s=sigma(k); m=m+s; if(m%s==0, print1(k ", "))) \\ _Donovan Johnson_, Oct 16 2013
%o A168127 (PARI) isok(k) = (sum(j=1, k, sigma(j)) % sigma(k)) == 0; \\ _Michel Marcus_, Feb 19 2020
%Y A168127 Cf. A000203, A024916, A168128, A168129, A168130.
%K A168127 nonn,more
%O A168127 1,2
%A A168127 _Jaroslav Krizek_, Nov 18 2009, Dec 04 2009
%E A168127 a(8)-a(10) from _Donovan Johnson_, Oct 16 2013
%E A168127 a(11)-a(14) from _Giovanni Resta_, Jun 06 2016
%E A168127 Name edited by _Michel Marcus_, Feb 19 2020