n!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
264: | \[264!!!!+1\] | 67 × 1499 × 11467 × 251833199 × 1531575998281004220191546527219<31> × 6671996887453480257304669223114033886928951431883536252203538060279018624978570618511<85> |