n!! - 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
123: | \[123!!-1\] | 2 × 59671 × 205208023746637<15> × 3170628934727436297166797151285899869<37> × 133652372205419113091873587172801117087051935499<48> |