Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
80: | \[{5^{80}-1\over4}\] | 24 × 3 × 11 × 13 × 17 × 41 × 71 × 241 × 313 × 521 × 9161 × 11489 × 25601 × 632133361 × 909456847814334401<18> |