Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 129: | \[{5^{129}-1\over4}\] | 31 × 18471511 × 1644512641 × 172827552198815888791<21> × 43955934961951833386625799<26> × 51349797354047205216257689<26> |