The limit in the question above can be found by simplifying ratios of consecutive repeated derivatives of $\frac{1}{\zeta(s)}$. ------------------------------------------------- My recent thoughts: See: https://mathoverflow.net/a/439430/25104 Let: $$\rho=\frac{1}{1-\frac{A}{B}}+\frac{1}{n}+s$$ Then according to Mathematica 8.0.1 the following: $$\tag{1}$$ $$\text{Reduce}\left[\rho=\frac{1}{1-\frac{A}{B}}+\frac{1}{n}+s\land \frac{1}{1-\frac{A}{B}}+\frac{1}{n}+s=\left(-s+\frac{1}{1-\frac{B}{A}}-\frac{1}{n}\right)^*\land B\neq 0\land \Re(\rho)\geq 0\land \Re(\rho)\leq 1,\Re(\rho)\right]$$ reduces to the conditions: $$\tag{2}$$ $A=\frac{B \cdot n \cdot \rho -B \cdot n \cdot s+B (-(n+1))}{n \cdot \rho-n \cdot s-1}$ $\land \left(\left(\Im(\rho)<\Im(s)\land \Re(\rho)=\frac{1}{2}\land (\Re(B)<0\lor (\Re(B)=0\land (\Im(B)<0\lor \Im(B)>0))\lor \Re(B)>0)\right)\lor \left(\Im(\rho)=\Im(s)\land \left(\left(\Re(s)<\frac{n-2}{2 n}\land \Re(\rho)=\frac{1}{2}\land (\Re(B)<0\lor (\Re(B)=0\land (\Im(B)<0\lor \Im(B)>0))\lor \Re(B)>0)\right)\lor \left(\Re(s)>\frac{n-2}{2 n}\land \Re(\rho)=\frac{1}{2}\land (\Re(B)<0\lor (\Re(B)=0\land (\Im(B)<0\lor \Im(B)>0))\lor \Re(B)>0)\right)\right)\right)\lor \left(\Im(\rho)>\Im(s)\land \Re(\rho)=\frac{1}{2}\land (\Re(B)<0\lor (\Re(B)=0\land (\Im(B)<0\lor \Im(B)>0))\lor \Re(B)>0)\right)\right)\land 0\leq \Re(\rho)\leq 1$ >So in other words there are choices of $A$, $B$ and the starting point $s$ where $\Re(\rho) = 1/2$, but the conditions above must be satisfied in order for the following equation: $$\lim_{n \rightarrow \infty}\left( \frac{1}{1-\frac{A}{B}}+\frac{1}{n}+s=\left(-s+\frac{1}{1-\frac{B}{A}}-\frac{1}{n}\right)^*\right)$$ to be true. In the case of the Riemann zeta function we would write: $$A=\sum _{k=1}^n \frac{(-1)^{k-1} \binom{n-1}{k-1}}{\zeta \left(\frac{k}{n}+s\right)} \tag{3}$$ $$B=\sum _{k=1}^n \frac{(-1)^{k-1} \binom{n-1}{k-1}}{\zeta \left(\frac{k}{n}+s+\frac{1}{n}\right)} \tag{4}$$ The parentheses with the star: $$\left(\right)^*$$ is the complex conjugate. How to show this in the case of the Riemann zeta function I don't know. Demonstration in Mathematica 8.0.1: (* Mathematica start *) Clear[A, B, n, k, s]; n = 20; s = 0; A = Sum[(-1)^(k - 1)*Binomial[n - 1, k - 1]/Zeta[s + k/n], {k, 1, n}]; B = Sum[(-1)^(k - 1)*Binomial[n - 1, k - 1]/Zeta[s + k/n + 1/n], {k, 1, n}]; "The first trivial zero with the zero of the conjugated limit shifted \ by 1 and with opposite sign:" Conjugate[-s - 1/n + 1/(1 - B/A)]; N[%, n] s + 1/n + 1/(1 - A/B); N[%, n] Clear[A, B, n, k, s]; n = 20; s = (1/3 + 14*I); A = Sum[(-1)^(k - 1)*Binomial[n - 1, k - 1]/Zeta[s + k/n], {k, 1, n}]; B = Sum[(-1)^(k - 1)*Binomial[n - 1, k - 1]/Zeta[s + k/n + 1/n], {k, 1, n}]; "The first non-trivial zero:" Conjugate[-s - 1/n + 1/(1 - B/A)]; N[%, n] s + 1/n + 1/(1 - A/B); N[%, n] "The conditions to be proven for the case of the Riemann zeta function:" Clear[s, A, B, n, z, k]; n = 19; Reduce[rho == s + 1/n + 1/(1 - A/B) && s + 1/n + 1/(1 - A/B) == Conjugate[-s - 1/n + 1/(1 - B/A)] && B != 0 && Re[rho] >= 0 && Re[rho] <= 1, Re[rho]] (*end*)