Base 18 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 74: | \[{18^{74}-1\over17}\] | 19 × 1259 × 157991 × 10375318069755905859690041706382489471961<41> × 1164939463722239475169554761379636729267089<43> |