Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
101: | \[{21^{101}-1\over20}\] | 2782147 × 5766091 × 322064357 × 9169578247930711724838223927<28> × 36945809153030964318516966609973698395187560924157000812220580201578519173448190367<83> |