Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
148: | \[{21^{148}-1\over20}\] | 22 × 11 × 13 × 17 × 149 × 593 × 31081 × 1681762703 × 7995105693353508392600118377453099<34> × 379919184478057330357419845346252603881265273961<48> × 1788811503934407101186498308824780458046366903126234228620483937887212343860808538302796253<91> |