%I A029767
%S A029767 0,1,3,14,90,744,7560,91440,1285200,20603520,371226240,
%T A029767 7428153600,163459296000,3923502105600,102017281766400,
%U A029767 2856571067750400,85698439706880000,2742370993410048000
%N A029767 (n-1)!*(2^n-1).
%C A029767 Labeled octupi with n nodes.
%D A029767 F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like 
               Structures, Camb. 1998, pp. 12, 55, 409.
%D A029767 R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see 
               Example 5.1.5.
%H A029767 INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=498">
               Encyclopedia of Combinatorial Structures 498</a>
%H A029767 INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=777">
               Encyclopedia of Combinatorial Structures 777</a>
%F A029767 (n-1)!*(2^n-1). E.g.f.: log(1-x)-log(1-2*x).
%F A029767 In Maple notation, representation as an infinite sum: a(n)=sum((n+k)!/
               ((k+1)!*2^k), k=0..infinity)/2, n=1, 2... Representation as n-th 
               moment of a positive function on a positive half-axis: a(n)=int(x^n*1/
               2*exp(-x)/x*(2*exp(1/2*x)-2), x=0..infinity), n=1, 2... - Karol A. 
               Penson (penson(AT)lptl.jussieu.fr), Oct 15 2002
%p A029767 with(combinat):seq((stirling1(j+1,1)*(stirling2(j+2, 2))*(-1)^j), j=-1..16); 
               - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 30 2007
%Y A029767 Sequence in context: A081005 A074518 A088789 this_sequence A120056 A125788 
               A101220
%Y A029767 Adjacent sequences: A029764 A029765 A029766 this_sequence A029768 A029769 
               A029770
%K A029767 nonn,easy
%O A029767 0,3
%A A029767 N. J. A. Sloane (njas(AT)research.att.com).