%I #7 Jul 30 2019 19:28:52
%S 1,1,6,6,6,42,78,114,366,870,1806,4470,10374,29490,70422,172050,
%T 443670,1203270,3079590,7634310,19822470,53513466,138825006,355353522,
%U 932324478,2521602582,6627329070,17259334422,45447231174,124012157154,328387674390
%N a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=a(2)=1 and a(3)=6.
%K nonn
%O 1,3
%A _Clark Kimberling_
%E Offset corrected and title improved by _Sean A. Irvine_, Jul 30 2019