%I #3 Mar 30 2012 18:36:56
%S 1,1,2,6,28,216,2864,66656,2760896,205824384,27886535424,
%T 6924055315968,3173107641551872,2700294145104025600,
%U 4289542333320782426112,12777557344991526923034624,71652489091220599890081005568
%N Column 0 of triangle A118024; also, column 0 of the matrix square of A118024 equals this sequence shifted 1 place left.
%F a(n) = Sum_{k=0..n-1} 2^(k*(n-1-k))*a(k)*a(n-1-k) for n>0 with a(0)=1.
%Y Cf. A118024.
%K nonn
%O 0,3
%A _Paul D. Hanna_, Apr 10 2006