Base 7 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 213: | \[{7^{213}-1\over6}\] | 3 × 19 × 968299 × 582053568181<12> × 990643452963163<15> × 169002145064468556765676975247413756542145739<45> × 1274759667849259732505774376326193816317726317<46> × 24640304627535595210208716854848978157699652842397850563<56> |