%I #4 Mar 30 2012 18:56:54
%S 1,3,9,30,102,360,1290,4704,17334,64512,241836,912384,3459876,
%T 13178988,50389236,193295652,743610528,2867892588,11085281328,
%U 42933166380,166575534264,647329281456,2519234973996,9817121868084
%N a(n)=(1/2)*T(2n+1,n+1), where T is given by A048113.
%K nonn
%O 2,2
%A _Clark Kimberling_