Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 163: | \[{4^{163}-1\over3}\] | 150287 × 704161 × 110211473 × 11281292593<11> × 27669118297<11> × 1023398150341859<16> × 36230454570129675721<20> × 337570547050390415041769<24> |