Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
158: | \[{3^{158}-1\over2}\] | 22 × 66361 × 432853009 × 327220181191<12> × 392038110671<12> × 145171177264407947<18> × 567239060331150635317<21> |