Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 168: | \[{4^{168}-1\over3}\] | 3 × 5 × 72 × 13 × 17 × 29 × 43 × 97 × 113 × 127 × 241 × 257 × 337 × 673 × 1429 × 2017 × 3361 × 5153 × 5419 × 14449 × 15790321 × 25629623713<11> × 54410972897<11> × 88959882481<11> × 1538595959564161<16> |