n!!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 391: | \[391!!!!!+1\] | 104953 × 15721694971<11> × 21914293210636112161<20> × 9508779245275157950512759856019981731<37> × 165144341549210745371069833110976065620148401<45> × 1720376083007172641387065776714926119219870029484514729<55> |