Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 317: | \[{4^{317}-1\over3}\] | 9511 × 326330579 × 491981122308467411<18> × 587492521482839879<18> × 4868122671322098041565641<25> × 9815639231755686605031317440031161584572466128599<49> × 554346309198841189738200247725749800421156685578702545439230498849139<69> |