Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 196: | \[{4^{196}-1\over3}\] | 5 × 17 × 29 × 43 × 113 × 127 × 197 × 7057 × 273617 × 1007441 × 15790321 × 375327457 × 19707683773<11> × 1405628248417<13> × 4363953127297<13> × 4432676798593<13> × 4981857697937<13> × 364565561997841<15> |