Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
143: | \[{21^{143}-1\over20}\] | 79 × 189437 × 516094151 × 197647219771<12> × 17513875027111<14> × 713255542756934588000409316079479675200443737<45> × 3133215050775538159999253890862035621216929079706901880925831712192141277620814505531687549750066100763<103> |