n!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
221: | \[221!!!!+1\] | 2 × 1835651240427436803681154796611807066143377<43> × 13525641099261865624459851900121272752803647096007976808013444969<65> |