n!! - 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 128: | \[128!!-1\] | 549319 × 6049342654573<13> × 11365547657190728087<20> × 61974559219203920426556243307850695609257373309203481832078089131413371<71> |