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%I #3 Mar 30 2012 18:36:45
%S 1,2,7,40,324,3336,41192,590480,9623944,175703056,3552295752,
%T 78802665120,1903505233064,49743146641616,1398474578414632,
%U 42092742475096960,1350629892258170184,46025643554111478576
%N Row sums of triangle A105623.
%C A105623 equals the matrix square-root of triangle A105615.
%o (PARI) {a(n)=local(R,M=matrix(n+3,n+3,m,j,if(m>=j,if(m==j,1,if(m==j+1,-2*j, polcoeff(1/sum(i=0,m-j,(2*i)!/i!/2^i*x^i)+O(x^m),m-j)))))^-1); R=(M+M^0)/2;for(i=1,floor(2*log(n+2)),R=(R+M*R^(-1))/2); return(if(n<0,0,sum(k=0,n,R[n+1,k+1])))}
%Y Cf. A105615, A105623.
%K nonn
%O 0,2
%A _Paul D. Hanna_, Apr 16 2005
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