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 A162828 #6 Nov 21 2013 12:49:39
%S A162828 10,18,30,45,60,72,90,110,126,135,180,210,234,270,315,360,450,510,558,
%T A162828 585,720,810,990,1260,1530,1710,1935,2610,3150,3960,5310,8010,16110
%N A162828 Positive numbers n such that 2*90*n/(90+n) are integers.
%t A162828 f[a_,b_]:=(a*b)/(a+b)*2; a=90;lst={};Do[If[f[a,n]==IntegerPart[f[a,n]], AppendTo[lst,n]],{n,9!}];lst
%t A162828 Select[Range[17000],IntegerQ[180 #/(#+90)]&] (* _Harvey P. Dale_, Sep 22 2011 *)
%Y A162828 Cf. A162688, A162689, A162690, A162691, A162692, A162693, A162694, A162817, A162818, A162819, A162820, A162821, A162822, A162823, A162824, A162825, A162826
%K A162828 nonn,fini,full
%O A162828 1,1
%A A162828 _Vladimir Joseph Stephan Orlovsky_, Jul 13 2009
%E A162828 Sign in definition flipped by _R. J. Mathar_, Jul 31 2009