Base 31 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
73: | \[{31^{73}-1\over30}\] | 30223 × 122840087453<12> × 197340338942587<15> × 833039147209543<15> × 404318326024801439191676313735836288644493580299053616879363447<63> |