Search: id:A052850 Results 1-1 of 1 results found. %I A052850 %S A052850 0,2,5,20,114,864,8280,96480,1325520,20966400,374855040,7468070400, %T A052850 163938297600,3929729126400,102104460057600,2857878742118400, %U A052850 85719362496768000,2742726680838144000,93247371837075456000 %N A052850 A simple grammar. %H A052850 INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 818 %F A052850 E.g.f.: (-x-ln((-1+x)/(-1+2*x))+ln((-1+x)/(-1+2*x))*x)/(-1+x) %F A052850 Recurrence: {a(1)=2, a(2)=5, a(3)=20, a(4)=114, (2*n^3-2*n)*a(n)+(-3*n^2+2*n+5)*a(n+1)+(-2+n)*a(n+2)} %p A052850 spec := [S,{B=Sequence(Z,1 <= card),C=Cycle(B),S=Union(B,C)},labeled]: seq(combstruct[count](spec,size=n), n=0..20); %Y A052850 Sequence in context: A019536 A129949 A127065 this_sequence A000130 A009599 A112833 %Y A052850 Adjacent sequences: A052847 A052848 A052849 this_sequence A052851 A052852 A052853 %K A052850 easy,nonn %O A052850 0,2 %A A052850 encyclopedia(AT)pommard.inria.fr, Jan 25 2000 Search completed in 0.001 seconds