Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
291: | 13 × 76631 × 189733 × 1693621 × 80640757 × 2549755542947<13> × 184812684901540537<18> × 48845962828028421155731228333<29> × 5852407890668586529163364311233328351058899596487336893<55> |