Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 261: | \[{20^{261}-1\over19}\] | 59 × 349 × 421 × 929 × 8179 × 10789 × 143609 × 564979 × 1177459 × 10220239 × 64008001 × 466307299 × 71353204641689<14> × 382963797404731<15> × 96300162662699234956876309<26> × 3605403851353821123741083595382953185544609831777342451<55> × [992519819464950999005511173045151157199431534863578336168408868138009790540090359195248017411269133891411428303061508116586190108986039627301058496921364790844858147713321<171>] |