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 A157051 #19 Sep 21 2019 14:40:26
%S A157051 0,0,0,1,3,16,95,809,10935,260350,11712539,1006674967,164059617696,
%T A157051 50335905627489,29003487431654737,31397381142185989848,
%U A157051 63969560113210957966315,245871831682083553779103249,1787331725248899067681312999794,24636021429399867654036551645873645,645465483198722799426625560872826564232
%N A157051 Number of connected unlabeled non-bipartite graphs on n nodes.
%C A157051 Inverse Euler transform of A157016.
%H A157051 Andrew Howroyd, <a href="/A157051/b157051.txt">Table of n, a(n) for n = 0..50</a>
%F A157051 a(n) = A001349(n) - A005142(n).
%t A157051 A001349 = Cases[Import["https://oeis.org/A001349/b001349.txt", "Table"], {_, _}][[All, 2]];
%t A157051 A005142 = Cases[Import["https://oeis.org/A005142/b005142.txt", "Table"], {_, _}][[All, 2]];
%t A157051 a[n_] := A001349[[n + 1]] - A005142[[n + 1]];
%t A157051 a /@ Range[0, 50] (* _Jean-François Alcover_, Sep 21 2019 *)
%K A157051 nonn
%O A157051 0,5
%A A157051 _Max Alekseyev_, Feb 22 2009
%E A157051 a(0) corrected, a(18)-a(20) added by _Max Alekseyev_, Jun 24 2013