n!! - 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 251: | \[251!!-1\] | 2 × 2429971 × 14008231 × 14701647579547<14> × 98944260114890563081<20> × 15881411782005932613158969<26> × [64428007473752130391836901119414708294961946858221852215207506939501080484723366467471317764303040582432637017347761752617156660875826819398985489003213707411480506446600133539<176>] |