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 A347690 #15 Sep 20 2021 06:32:39
%S A347690 1,3,8,10,12,14,16,21,22,24,30,31,34,36,37,38,39,42,43,46,51,52,55,59,
%T A347690 60,61,62,66,67,68,72,73,75,77,78,82,83,87,91,93,96,97,98,99,101,102,
%U A347690 105,110,115,121,124,125,129,135,136,139,140,143,145,147,151
%N A347690 Values of k such that (product of first k squarefree numbers) / (sum of first k squarefree numbers) is an integer.
%C A347690 a(n) is the number of terms in the numerator (or denominator) when A322609(n) is found.
%H A347690 Harvey P. Dale, <a href="/A347690/b347690.txt">Table of n, a(n) for n = 1..1000</a>
%t A347690 Module[{nn=4000,sf},sf=Select[Range[nn],SquareFreeQ];Table[ If[ IntegerQ[ Times@@Take[sf,n]/Total[Take[sf,n]]],n,Nothing],{n,Length[sf]}]] (* _Harvey P. Dale_, Sep 19 2021 *)
%Y A347690 Cf. A005117, A111059, A173143, A322607, A322608.
%K A347690 nonn
%O A347690 1,2
%A A347690 _N. J. A. Sloane_, Sep 19 2021
%E A347690 More terms from _Harvey P. Dale_, Sep 19 2021