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 A162826 #5 Mar 19 2019 14:54:18
%S A162826 12,15,20,30,36,40,60,84,90,100,120,140,165,180,228,240,300,340,390,
%T A162826 420,540,660,740,840,1140,1380,1740,2340,3540,7140
%N A162826 Positive numbers n such that 2*60*n/(60+n) are integers.
%t A162826 f[a_,b_]:=(a*b)/(a+b)*2; a=60;lst={};Do[If[f[a,n]==IntegerPart[f[a,n]], AppendTo[lst,n]],{n,9!}];lst
%t A162826 Select[Range[8000],IntegerQ[(120#)/(60+#)]&] (* _Harvey P. Dale_, Mar 19 2019 *)
%Y A162826 Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817, A162818, A162819, A162820, A162821, A162822, A162823, A162824, A162825
%K A162826 nonn,fini,full
%O A162826 1,1
%A A162826 _Vladimir Joseph Stephan Orlovsky_, Jul 13 2009
%E A162826 Sign in definition flipped by _R. J. Mathar_, Jul 31 2009