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%I #17 Jan 04 2021 19:53:27
%S 2,16,168,1920,23360,296448,3880576,52015104,710360064,9849036800,
%T 138270871552,1961643540480,28079294676992,405035709890560,
%U 5881791327928320,85917550984036352,1261588096997916672,18611082818941353984
%N Number of And/Or trees with n internal nodes that compute the Boolean value True.
%H Vincenzo Librandi, <a href="/A181914/b181914.txt">Table of n, a(n) for n = 1..200</a>
%H B. Chauvin, P. Flajolet, et al., <a href="http://dx.doi.org/10.1017/S0963548304006273">And/Or Tree Revisited</a>, Combinat., Probal. Comput. 13 (2004) 475-497
%F G.f.: (2-sqrt(2+16*x+2*sqrt(1-16*x)))/(8*x).
%F Recurrence: (n+1)*(2*n+1)*a(n) = 12*n*(3*n-1)*a(n-1) - 48*(n^2-5*n+5)*a(n-2) - 128*(n-2)*(2*n-5)*a(n-3). - _Vaclav Kotesovec_, Oct 20 2012
%F a(n) ~ 16^n/(sqrt(3*Pi)*n^(3/2)). - _Vaclav Kotesovec_, Oct 20 2012
%p g := (2-sqrt(2+16*z+2*sqrt(1-16*z)))/8/z ; seq(coeftayl(%,z=0,n),n=1..20) ;
%t Rest[CoefficientList[Series[(2-Sqrt[2+16*x+2*Sqrt[1-16*x]])/(8*x), {x, 0, 20}], x]] (* _Vaclav Kotesovec_, Oct 20 2012 *)
%K nonn
%O 1,1
%A _R. J. Mathar_, Apr 01 2012
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