Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
218: | \[{3^{218}-1\over2}\] | 22 × 1091 × 521402591 × 1992772009 × 3499901929 × 239789806103<12> × 5933538193981<13> × 7696680097963<13> × 27866471458012723<17> × 10624346875389299603<20> |