Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 42: | \[{28^{42}-1\over27}\] | 3 × 29 × 43 × 113 × 271 × 631 × 757 × 2269 × 13007 × 29443 × 35771 × 132679 × 4422461 × 223934956756993189<18> |