n!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 261: | \[261!!!+1\] | 7911268926631872257<19> × 2508626850967308120409<22> × 56223414819638977163831<23> × 1400259518000903026021226169915887<34> × 2470118688061502281884890716611739<34> × 176540346178048351769505388073829264920244419<45> |