n!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 251: | \[251!!!!+1\] | 27 × 1283 × 297040321658296375663560466567257810177884514154990908826356860682540745491528094179246050940132445455350408806646641399<120> |