n!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 208: | \[208!!!!+1\] | 53 × 113 × 533830457 × 49211782924736923<17> × 10397793312324709167941072654876041903730377199711752865812995048317519<71> |