n!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
153: | \[153!!+1\] | 2 × 8783 × 11191289284713071553703958156946630947<38> × 13954614986569592561408435447660843023<38> × 513368871198917870812339195230106604795642747579315301731<57> |