Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 687: | \[{4^{687}-1\over3}\] | 3 × 7 × 6871 × 1504073 × 18754643 × 20492753 × 2104809991 × 779704994617<12> × 59833457464970183<17> × 168813603058115744761<21> × 81514868646704507393379787<26> × 175932323679511304414371921<27> × 467795120187583723534280000348743236593<39> × 15333417141003794339164342447265426158851946182451963484372297<62> × 23122893068559620083520897911061756854062924897573799772499037716952423146885169<80> × 41788952991139118639110460647465055080950855027758632702923742575763463332284772733328169713812071<98> |