%I #11 Apr 30 2014 01:31:34
%S 1,4,28,220,1819,15484,134320,1180764,10482340,93766288,843822148,
%T 7631018564,69291185474,631334484200,5769124912320,52851389067420,
%U 485242722376524,4463782855666480,41133265444555120
%N C(4n,n) - C(4n,n-4).
%F G.f.: (g-2)*(2-2*g+g^2)*g^2/(3*g-4) where g = 1+x*g^4 is the g.f. of A002293. - Mark van Hoeij, Nov 11 2011
%Y a(n) = T(4n, n), where T is defined in A026022.
%K nonn
%O 0,2
%A _Clark Kimberling_
%E More terms from _Ralf Stephan_, Jan 09 2005