Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 521: | \[{3^{521}-1\over2}\] | 394004822498482103<18> × 1113152871547083276871904557<28> × 433598094341851039126807983969436278038008780825086953001394407531050013012083278631834972318550974431326162340745933811935520060368207930863528293075538258146829553622723637770628450951970290566674610131<204> |