Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 193: | \[{3^{193}-1\over2}\] | 6563 × 29723 × 2346066378779<13> × 218246094772601642186973037<27> × 607981469094652492202396647678317419649770543<45> |