n!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 128: | \[128!!+1\] | 712 × 127 × 131 × 25889 × 581577956130858314539915405227514431691397<42> × 1853624211357712425429620258322526699333701042238517441<55> |