n!!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
245: | \[245!!!!!+1\] | 6133 × 24821 × 299389 × 2059016214293<13> × 2480819765668421796257<22> × 1495249102019112528143399<25> × 31041197810332287512440687<26> |