Base 7 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 129: | \[{7^{129}-1\over6}\] | 3 × 19 × 10837 × 63350976270733<14> × 166003607842448777<18> × 2192537062271178641<19> × 175446584281395198837259<24> × 694623197348682715265952229891<30> |