Base 31 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 91: | \[{31^{91}-1\over30}\] | 2549 × 42407 × 1661479 × 2426789 × 7908811 × 917087137 × 473516688426601<15> × 1122399563430440797573237387545143<34> × 102672478567468007638784142574112507144367962863477<51> |