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 A248832 #39 Oct 29 2014 13:17:01
%S A248832 2,6,16,34,72,122,214,338,516,734,1062,1438,1970,2586,3322,4186,5322,
%T A248832 6566,8152,9898,11896,14114,16838,20254,23982,28196,32746,38108,43710,
%U A248832 50242,57286,64990,73238,82326,91846,102698,114234,126706,139818
%N A248832 The sum of denominators of unreduced mediants in Farey sequences of orders 1,2,..,n.
%H A248832 Wikipedia, <a href="http://en.wikipedia.org/wiki/Mediant_(mathematics)">Mediant</a>.
%H A248832 Wikipedia, <a href="http://en.wikipedia.org/wiki/Farey_sequence">Farey Sequence</a>.
%F A248832 a(n) = 2*Sum_{k= 1,2,3,4..n} A213544(k).
%e A248832 For n=4, the unreduced mediants are 1/2, 2/4, 5/10, 9/18, hence the sum of denominators is 2+4+10+18 = 34.
%Y A248832 Cf. A007306, A006843.
%K A248832 nonn,easy
%O A248832 0,1
%A A248832 _Nehul Yadav_, Oct 15 2014