Base 17 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 69: | \[{17^{69}-1\over16}\] | 47 × 307 × 25225573 × 9559382330644273<16> × 26552618219228090162977481<26> × 5385687325711213602812791946461<31> |