Base 31 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 68: | \[{31^{68}-1\over30}\] | 26 × 13 × 37 × 103 × 1399577 × 224499664484159761<18> × 6841661642646463343047<22> × 751670559138758105956097<24> × 1682325489672499143634073<25> |