Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
173: | \[{15^{173}-1\over14}\] | 923096729690317321<18> × 9240237956752269182353267070402853452904883<43> × 2436292415350737343614929705601991677664442537358603009706427924604639376665290020919017276438327799086249492470369869986396553381727204817987<142> |