Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 197: | \[{5^{197}-1\over4}\] | 470323176131<12> × 362204827770839<15> × 730600976247394424186287179916007406731365107091939767543519557253021863903691190053568311733456440015345138409<111> |