At first sight, the following series expression seems to converge everywhere:
$$f(s) = \sum_{n=2}^\infty \frac{\zeta(n)-1}{n^s + n^{1-s}} \tag{1}$$
For $s$ real we obtain a nice Gaussian shaped curve:
however for $s=\frac12 + ti, N = 6$ we get (note the graph quickly becomes 'messier' for higher $N$):
The location of the infinite number of poles can be easily explained. These are induced when $n^s + n^{1-s}=0$ for a certain integer $n$ and this can only occur when $\Re(s)=\frac12$.
From the graph we can also see some roots lying between the poles and based on (limited) numerical evidence I like to conjecture that these also all reside on the critical line $\Re(s)=\frac12$. Could the latter be within reach of a proof (my hope is that this is somehow related to the location of the poles) or will this be just as hard as the RH?


Similar looking like I said
– mick Sep 10 '24 at 23:08