Base 16 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 221: | \[{16^{221}-1\over15}\] | 53 × 137 × 157 × 443 × 953 × 1327 × 1613 × 2731 × 8191 × 26317 × 43691 × 131071 × 1210509821 × 2291059412513<13> × 4714692062809<13> × 6670914925963435577<19> × 1118498440898880562062959177194663477<37> × 2380142106509122200127345885819001687213<40> × 4507513575406446515845401458366741487526913<43> × 2365454398418399772605086209214363458552839866247069233<55> |