Base 16 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 51: | \[{16^{51}-1\over15}\] | 3 × 7 × 13 × 103 × 137 × 307 × 409 × 953 × 2143 × 2857 × 3061 × 6529 × 11119 × 13669 × 26317 × 43691 × 131071 × 1326700741 |