Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 281: | \[{5^{281}-1\over4}\] | 631100202961413821<18> × 10195602784853557560562134817849622978910929654525953132499556883513981723116004218984955825032305432898964333146255670715061564908151853501866060734987406159465751290832144211261<179> |