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Expansion of e.g.f.: exp(x*(1+x)^x)
4

%I #14 Nov 10 2024 12:54:14

%S 1,1,1,7,13,101,361,2269,18201,48817,1436401,-2283269,157443397,

%T -826037939,21355181849,-160556822999,3084325024561,-22223879489055,

%U 291212769688417,2180748026158255,-118745486165378819,4884619264768661461,-140063412525642293687,4020051993317128467029

%N Expansion of e.g.f.: exp(x*(1+x)^x)

%F a(n)=n!*sum(m=1..n, sum(k=0..n-m, (m^k*stirling1(n-m-k,k))/(n-m-k)!)/m!), n>0, a(0)=1.

%t With[{nn=30},CoefficientList[Series[Exp[x (1+x)^x],{x,0,nn}],x] Range[ 0,nn]!] (* _Harvey P. Dale_, Oct 13 2019 *)

%o (Maxima)

%o a(n):=if n=0 then 1 else n!*sum(sum((m^k*stirling1(n-m-k,k))/(n-m-k)!,k,0,n-m)/m!,m,1,n);

%K sign,changed

%O 0,4

%A _Vladimir Kruchinin_, Dec 12 2011

%E Definition clarified by _Harvey P. Dale_, Oct 13 2019