Base 13 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 74: | \[{13^{74}-1\over12}\] | 2 × 7 × 223 × 1481 × 21017 × 152219 × 67495678093<11> × 1548921490187<13> × 4287755796749<13> × 31964044249933<14> × 10626791079749447<17> |