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A081624 Number of 8-level labeled rooted trees with n leaves. 5


%S 1,1,8,92,1380,25488,558426,14140722,406005804,13024655442,

%T 461451524934,17886290630832,752602671853068,34152212772528222,

%U 1662095923363838817,86335146917372644026,4766427291743224251474,278658370977555551901990

%N Number of 8-level labeled rooted trees with n leaves.

%D J. Ginsburg, Iterated exponentials, Scripta Math., 11 (1945), 340-353.

%D T. Hogg and B. A. Huberman, Attractors on finite sets: the dissipative dynamics of computing structures, Phys. Review A 32 (1985), 2338-2346.

%H Alois P. Heinz, <a href="/A081624/b081624.txt">Table of n, a(n) for n = 0..150</a>

%F E.g.f.: exp(exp(exp(exp(exp(exp(exp(exp(x)-1)-1)-1)-1)-1)-1)-1).

%o (PARI) a(n)=local(X); if(n<0,0,X=x+x*O(x^n); n!*polcoeff(exp(exp(exp(exp(exp(exp(exp(exp(X)-1)-1)-1)-1)-1)-1)-1),n))

%Y Cf. A000110, A000258, A000307, A000357, A001669.

%Y Column k=7 of A144150.

%K nonn

%O 0,3

%A _Benoit Cloitre_, Apr 23 2003

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Last modified April 18 16:52 EDT 2019. Contains 322216 sequences. (Running on oeis4.)