%I A130678
%S A130678 2,2,74,11666,5343338,5664481490,11994898758122,45768613243457234
%N A130678 Number of reduced BDDs (binary decision diagrams) with two nodes on each 
               level except the top.
%C A130678 Can be computed in polynomial time, but probably not "easily".
%D A130678 D. E. Knuth, The Art of Computer Programming, Volume 4, to appear as 
               an exercise in Section 7.1.4.
%Y A130678 Sequence in context: A086204 A037292 A028372 this_sequence A156523 A156511 
               A133295
%Y A130678 Adjacent sequences: A130675 A130676 A130677 this_sequence A130679 A130680 
               A130681
%K A130678 nonn
%O A130678 1,1
%A A130678 D. E. Knuth, Jun 29 2007