Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 63: | \[{15^{63}-1\over14}\] | 7 × 43 × 127 × 241 × 541 × 883 × 21061 × 123229 × 399043 × 1743463 × 1470374630929<13> × 2817034275427<13> × 269297040407347<15> |