Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
74: | \[{15^{74}-1\over14}\] | 24 × 223 × 593 × 4441 × 32217011 × 5928049943<10> × 2474070455887<13> × 29645965890637091<17> × 582492120825067581276282544339<30> |