%I #10 Mar 30 2012 16:51:56
%S 0,0,1,2,5,9,22,48,118,288
%N Arises in analysis of Algorithm O for generating oriented trees.
%D D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.2.1.6, p. 802.
%K nonn
%O 1,4
%A _N. J. A. Sloane_, Aug 03 2011