Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 338: | \[{4^{338}-1\over3}\] | 5 × 53 × 157 × 677 × 1613 × 2731 × 4057 × 8191 × 180201997 × 1259036730797<13> × 6740339310641<13> × 615946323850313<15> × 4929910764223610387<19> × 408946876729703992293841657<27> × 18526238646011086732742614043<29> × 215656329382891550920192462661<30> × 3340762283952395329506327023033<31> |