Largest prime factor in the subfactorial of n.

Terms

a(0) =2a(1) =3a(2) =11a(3) =53a(4) =103a(5) =163a(6) =41a(7) =16481a(8) =1468457a(9) =1456321a(10) =139241a(11) =1796801a(12) =34361893981a(13) =15549624751a(14) =461702183a(15) =65026777a(16) =893977617157a(17) =17562703393a(18) =482455223267a(19) =85836476923a(20) =352463a(21) =809358677