Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 98: | \[{4^{98}-1\over3}\] | 5 × 29 × 43 × 113 × 127 × 197 × 19707683773<11> × 4363953127297<13> × 4432676798593<13> × 4981857697937<13> |