%I #7 Oct 24 2019 16:01:04
%S 1,6,20,152,528,4416,15488,135552,477440,4289536,15144960,138407936,
%T 489431040,4526702592,16024403968,149528084480,529747476480,
%U 4977103994880,17643662213120,166668216041472,591119702294528,5608619676532736
%N a(n) = A027144(2n-1, n-1).
%K nonn
%O 1,2
%A _Clark Kimberling_