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 A123117 #12 Apr 04 2014 10:46:54 %S A123117 2,8,70,722,8220,99820,1265204,16547220,221653776,3025553180, %T A123117 41931984034,588491482334,8346638665718,119447839104366, %U A123117 1722663727780132,25011714460877474,365301750223042066,5363288299585278800 %N A123117 A063865(4n-3). %H A123117 Ray Chandler, <a href="/A123117/b123117.txt">Table of n, a(n) for n = 1..835</a> (terms < 10^1000) %F A123117 a(n) = 2*A104456(n). %Y A123117 Cf. A063865, A060468, A104456. %K A123117 nonn %O A123117 1,1 %A A123117 _N. J. A. Sloane_, Jul 07 2008