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 A167571 #14 Jul 05 2015 20:24:31
%S A167571 1,6,54,680,11160,226800,5504688,155433600,5006655360,181193760000,
%T A167571 7279267564800,321452513141760,15477343917235200,806956698772224000,
%U A167571 45293698702796544000,2723112069367173120000,174590385277914250444800
%N A167571 The row sums of triangle A167569.
%C A167571 A167569 is the lower left triangle of the ED2 array A167560.
%H A167571 Vincenzo Librandi, <a href="/A167571/b167571.txt">Table of n, a(n) for n = 1..100</a>
%F A167571 a(n) = sum(4^(m-1)*(m-1)!*(n+m-1)!/(2*m-1)!, m=1..n).
%F A167571 a(n) = n!*(4^n - 1)/(2*n + 1). - _Peter Bala_, Jun 21 2013
%F A167571 E.g.f. 1/(4*sqrt(x))*log((1 - 3*x + 2*x^(3/2))/(1 - 3*x - 2*x^(3/2))). - _Peter Bala_, Jun 21 2013
%t A167571 Table[n! (4^n - 1) / (2 n + 1), {n, 1, 20}] (* _Vincenzo Librandi_, Jun 23 2013 *)
%Y A167571 A167560 is the ED2 array.
%Y A167571 Equals the row sums of triangle A167569.
%K A167571 easy,nonn
%O A167571 1,2
%A A167571 _Johannes W. Meijer_, Nov 10 2009