Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 316: | \[{4^{316}-1\over3}\] | 5 × 17 × 317 × 2687 × 504337 × 994769 × 202029703 × 1113491139767<13> × 381364611866507317969<21> × 201487636602438195784363<24> × 604462909806215075725313<24> × 15652605325219818652993083172107461429783643502979960839389487552451781198261880337<83> |