n!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
280: | \[280!!!!+1\] | 71 × 613781055882486173208884625121448262715725736913<48> × 383118037991190188808759172148295542963503184029562014073413183631803732629080748742623410887<93> |