n!!!! - 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
260: | \[260!!!!-1\] | 2452399 × 4577607583449027093965346127459914523918319873139203126709745168197208851381465131155724062988452689522169795901981692212401<124> |