Base 18 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 138: | \[{18^{138}-1\over17}\] | 73 × 19 × 47 × 139 × 307 × 599 × 3313 × 4831 × 7468009 × 20801237997245359<17> × 824418892380831861979<21> × 3913037558632733048069409307<28> × 47425584012916444409713229683<29> × 3335831283765997129468848570484932171598514072932729<52> |