Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
178: | \[{3^{178}-1\over2}\] | 22 × 179 × 264331 × 1125706177 × 1611479891519807<16> × 5042939439565996049162197<25> × 2444322641415331355533344283<28> |