Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 157: | \[{3^{157}-1\over2}\] | 9421 × 3381925092493<13> × 9891109125337566719<19> × 1283810768507270931382867729773882314783<40> |