Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 299: | \[{4^{299}-1\over3}\] | 47 × 599 × 2393 × 2731 × 8191 × 178481 × 2796203 × 9341359 × 14718679249<11> × 834490119087067<15> × 13444476836590589479<20> × 51441563151591093599<20> × 260242449712509916159<21> × 22263485343435683412693923533443917032613157943146077977190561<62> |