lim[x+sum[sum[sum[(i/2)^n (2i)^(m+n) stirlings1(m+n,n)/(m+n)! binom(-(m+n),j) (-i)^j x^(1 - n - 3 (j + m + n)) factorialpower((-3 (j + m + n)), -1 + n),{j,0,20}],{m,0,20}],{n,1,20}],x->(1.0+1/2)*π]