Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 69: | \[{15^{69}-1\over14}\] | 241 × 829 × 967 × 31741 × 434956681 × 80732172121<11> × 3046462151831565769<19> × 153908199071740625749971976183<30> |