Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
223: | \[{3^{223}-1\over2}\] | 54473097204950819531444809<26> × 229523806583019160757328140035039965995090154366780957756461054952218263816107757<81> |