Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
181: | \[{3^{181}-1\over2}\] | 90863 × 890159 × 1412740676235815729693013611798695493926336144083867368022228212267580445753<76> |