n!!!!! + 1
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 261: | \[261!!!!!+1\] | 2903 × 1270579 × 821823376234643<15> × 142146875868267729086073119422921925705455518880598710795442688022983589159082287<81> |