Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 245: | \[{4^{245}-1\over3}\] | 11 × 31 × 43 × 71 × 127 × 281 × 491 × 1471 × 86171 × 122921 × 4363953127297<13> × 4432676798593<13> × 15162868758218274451<20> × 50647282035796125885000330641<29> × 252359902034571016856214298851708529738525821631<48> |