Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 68: | \[{15^{68}-1\over14}\] | 25 × 113 × 137 × 443 × 29173 × 712573 × 1045002649 × 3395062589 × 6734509609<10> × 101462866544971<15> × 608605859277144821<18> |