n!! - 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 256: | \[256!!-1\] | 179 × 9769 × 4242929 × 10645869647280001<17> × 16925156269239853<17> × 1014064651814890539119<22> × [96794606301227658913322526638473524588169778974198046261228694122902529152652367264519738088903885043420617815490734178296957946708730280193297667876598489949639608362952321857715959174383<188>] |