%I #3 Mar 30 2012 16:49:44
%S 0,1,9,79,765,8311,100989,1362439,20246445,328972471,5805917469,
%T 110645911399,2265191981325,49589790516631,1156201277261949,
%U 28605950745797959,748605590542359405,20661245832389468791,599820758571599742429,18272940402442730318119,582867486201919540724685
%N a(n) = Sum(((k-1)/2)*k!*Stirling_2(n,k),k=1..n).
%F E.g.f.: (1/2)*( (1-exp(x))/(2-exp(x)) )^2.
%Y Equals A083384(n)/n.
%K nonn
%O 1,3
%A _N. J. A. Sloane_, Jun 08 2003
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