Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
139: | \[{15^{139}-1\over14}\] | 557 × 126491 × 402570254679080538585607733<27> × 75474539088975600452493022923034467952752989947695845287554333485123841459249237671767889638680092480568186615136742983361784371<128> |