Neutron–proton ratio and isotope stability

I have studied that most of the isotopes (not all of them!) with a neutron–proton ratio of $\ge 1.5$ are unstable; but it is obvious that this is not true in some cases like carbon-14 or technetium-99.

Is it possible for an isotope to have a neutron/proton ratio of more than 1.5 and still be stable? If yes, could you please give an example?