Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 154: | \[{4^{154}-1\over3}\] | 5 × 23 × 29 × 43 × 89 × 113 × 127 × 397 × 617 × 683 × 2113 × 8317 × 78233 × 869467061 × 3019242689 × 35532364099<11> × 76096559910757<14> × 581283643249112959<18> |