Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 177: | \[{3^{177}-1\over2}\] | 13 × 709 × 14425532687<11> × 489769993189671059<18> × 2224898159852613649<19> × 9736622508037946817946068730077829<34> |