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 A181798 #5 Mar 30 2012 17:27:19
%S A181798 1,6,12,12,24,30,36,48,56,72,96,108,132,144,150,180,182,192,216,288,
%T A181798 306,324,336,360,360,380,384,392,432,552,576,648,672,672,720,750,768,
%U A181798 792,864,870,900,972,992,1080,1092,1152,1296,1344,1406,1440,1452,1536,1584,1584
%N A181798 Terms of A181797 arranged in ascending order.
%C A181798 The natural density of positive integers m such that A003557(m) = A181799(n) equals 6/(a(n)*Pi^2).
%H A181798 Wikipedia, <a href="http://en.wikipedia.org/wiki/Natural_density">Natural density</a>
%F A181798 sum{n>=1} 1/a(n) = pi^2/6 = A013661.
%K A181798 nonn
%O A181798 1,2
%A A181798 _Matthew Vandermast_, Dec 05 2010