Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 157: | \[{15^{157}-1\over14}\] | 1571 × 227677817616311475823<21> × 4075234956970664636513337173<28> × 2170451462313835599923973352654821422229921555143692342338147574711259544586294830246707346013355474687540385813840732446876384620849<133> |