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 A332270 #35 May 03 2021 02:13:44
%S A332270 3,4,14,29,82,67117,86249,140064,185699,392081,2915083,6315155,
%T A332270 9723681,17754993,820165642,9388829301,143904506919,192738887697
%N A332270 Numbers k such that Sum_{j=1..k} j*floor(k/j) is divisible by k+1.
%C A332270 a(19) > 5*10^11. - _Giovanni Resta_, May 05 2020
%t A332270 q[n_] := Divisible[Sum[j * Floor[n/j], {j, 1, n}], n + 1]; Select[Range[100], q] (* _Amiram Eldar_, May 03 2021 *)
%o A332270 (PARI) for(k=1, 1e4, if(sum(j=1, k, k\j*j)%(k+1)==0, print1(k", ")))
%o A332270 (PARI) s=0; for(k=1, 1e7, s+=sigma(k); if(s%(k+1)==0, print1(k", ")))
%Y A332270 Cf. A000203, A024916, A056550.
%K A332270 nonn,more
%O A332270 1,1
%A A332270 _Seiichi Manyama_, May 04 2020
%E A332270 a(16)-a(18) from _Giovanni Resta_, May 05 2020