n!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
263: | \[263!!!!+1\] | 2 × 7255742918443<13> × 705915679978589<15> × 82861687393948843<17> × 5384958668823948201174067<25> × 185373165959846864780112762912798322963635765845696768813193349<63> |