Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
247: | \[{5^{247}-1\over4}\] | 191 × 6271 × 29641 × 3981071 × 305175781 × 893134065430622331883159985777080426121<39> × 73264607998188798376620748253610482190769<41> × 3916581678566130795968630368428499724365376308585023695226827857169<67> |