Base 18 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 69: | \[{18^{69}-1\over17}\] | 73 × 47 × 599 × 4831 × 7468009 × 20801237997245359<17> × 3335831283765997129468848570484932171598514072932729<52> |