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%I #7 Mar 31 2012 10:23:14
%S 1,1,2,3,-48,-1220,-19440,-69720,14407680,953539776,35565868800,
%T -210727440000,-201519805132800,-23287596250913280,
%U -1387143593335019520,70361372381908608000,36238719331572645888000,6110545675513945739673600,457510061917491552313344000,-86824257027562156263159398400,-44392403385021894430349721600000
%N Expansion of (1-exp(x))/(1+x^2-exp(x))=sum(n>=0, a(n)*x^n/n!^2)
%F a(n)=n!^2*sum(m=1..n-1, (m!*sum(k=1..n-m, (k!*stirling1(m+k,m)*stirling2(n-m,k))/(m+k)!))/(n-m)!)+n!^2.
%o (Maxima)
%o a(n):=n!^2*sum((m!*sum((k!*stirling1(m+k,m)*stirling2(n-m,k))/(m+k)!,k,1,n-m))/(n-m)!,m,1,n-1)+n!^2;
%K sign
%O 0,3
%A _Vladimir Kruchinin_, Jun 07 2011