n!! - 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 257: | \[257!!-1\] | 29 × 116981 × 157931 × 728191 × 9858370279<10> × [24741471005649277578625919507886461805489453953151424623715331619109328207049987846906427601346778048849341711829244318649795186592542269395429507270256227238279712896076792101696064235413807870275130595144836449917428218937763<227>] |