An example which is almost trivial: take the sequence $\{1,4,8,16,32\ldots\}$, i.e. powers of $2$ omitting two itself.  For real part of $s>0$, the Dirichlet series is a convergent geometric series, summing as
$$
\frac{1-2^s+4^s}{1-2^s}
$$
which has a meromorphic continuation.  The zeros are all purely imaginary, at
$$
\frac{\pi i(6n\pm1)}{3\log(2)},\qquad \text{integer } n
$$
if I've done the calculation correctly.