Base 18 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
59: | \[{18^{59}-1\over17}\] | 4295428888967<13> × 128998224914431<15> × 312278175742409<15> × 39128840454084865858255640571151<32> |