%I A052875
%S A052875 0,0,2,12,74,540,4682,47292,545834,7087260,102247562,1622632572,
%T A052875 28091567594,526858348380,10641342970442,230283190977852,
%U A052875 5315654681981354,130370767029135900,3385534663256845322
%N A052875 A simple grammar.
%C A052875 Stirling transform of A005359(n-1)=[0,0,2,0,24,0,...] is a(n-1)=[0,0,
               2,12,74,...]. - Michael Somos Mar 04 2004
%C A052875 Stirling transform of -(-1)^n*A052566(n-1)=[1,-1,4,-6,48,...] is a(n-1)=[1,
               0,2,12,74,...]. - Michael Somos Mar 04 2004
%C A052875 Stirling transform of A000142(n)=[0,2,6,24,120,...] is a(n)=[0,2,12,74,
               ...]. - Michael Somos Mar 04 2004
%C A052875 Stirling transform of A007680(n)=[2,10,42,216,...] is a(n+1)=[2,12,74,
               ...]. - Michael Somos Mar 04 2004
%H A052875 INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=846">
               Encyclopedia of Combinatorial Structures 846</a>
%F A052875 Second column of A084416: Sum_{i=2..n} i!*Stirling2(n, i) = A000670(n)-1. 
               - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 15 2003
%F A052875 E.g.f.: (exp(x)-1)^2/(2-exp(x)).
%p A052875 spec := [S,{B=Set(Z,1 <= card),C=Sequence(B,1 <= card),S=Prod(B,C)},labeled]: 
               seq(combstruct[count](spec,size=n), n=0..20);
%o A052875 (PARI) a(n)=if(n<0,0,n!*polcoeff(subst(y^2/(1-y),y,exp(x+x*O(x^n))-1),
               n))
%Y A052875 Sequence in context: A014351 A074616 A006936 this_sequence A037725 A037620 
               A121680
%Y A052875 Adjacent sequences: A052872 A052873 A052874 this_sequence A052876 A052877 
               A052878
%K A052875 easy,nonn
%O A052875 0,3
%A A052875 encyclopedia(AT)pommard.inria.fr, Jan 25 2000