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 A159271 #11 Mar 09 2014 05:55:36 %S A159271 17116004505600,75462255348480000,6219051710415667200, %T A159271 14031414189615513600,352444116692828160000,835095457414213632000, %U A159271 59485231752222033838080,64031599488357236736000 %N A159271 Numbers with abundancy index sigma(n)/n = 11/2. %H A159271 Michel Marcus, <a href="/A159271/b159271.txt">Table of n, a(n) for n = 1..117</a> %H A159271 G. P. Michon and M. Marcus, <a href="http://www.numericana.com/data/hpn11.htm">Hemiperfect numbers of abundancy 11/2</a> (table with factorizations). [From _Gerard P. Michon_, Jul 01 2009] %H A159271 Walter Nissen, <a href="http://upforthecount.com/math/abundance.html">Abundancy : Some Resources </a> %o A159271 (PARI) is(n)=sigma(n,-1)==11/2 \\ _Charles R Greathouse IV_, Mar 09 2014 %K A159271 nonn %O A159271 1,1 %A A159271 _M. F. Hasler_, Apr 21 2009