%I

%S 1,6,21,108,370,1908,6587,34248,119142,623700,2182818,11487528,

%T 40391988,213451560,753295635,3993910416,14136717574,75152083716,

%U 266650874678,1420670333640,5050926317724,26960309526744,96015725922014

%N a(n) = T(2n,n-1), T given by A026648.

%K nonn

%O 1,2

%A _Clark Kimberling_