Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 170: | \[{4^{170}-1\over3}\] | 52 × 11 × 31 × 41 × 137 × 953 × 1021 × 4421 × 26317 × 43691 × 131071 × 550801 × 23650061 × 7226904352843746841<19> × 9520972806333758431<19> × 26831423036065352611<20> |