Base 18 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 99: | \[{18^{99}-1\over17}\] | 73 × 23 × 199 × 991 × 16127 × 34327 × 51217 × 3611719 × 4893407785654797223<19> × 12042065697120681040605799<26> × 117206168731902676796790484884706056816111011068777<51> |