Base 8 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 215: | \[{8^{215}-1\over7}\] | 31 × 151 × 431 × 1721 × 9719 × 46441 × 2099863 × 731516431 × 4175568751 × 514851898711<12> × 1728221461577944661374351<25> × 11053036065049294753459639<26> × 83212524822005103181053031<26> × 297927289744047764444862191<27> × 8510131405590136091948615255367876121<37> |