Largest prime factor of n! + 1.

Terms

a(0) =2a(1) =2a(2) =3a(3) =7a(4) =5a(5) =11a(6) =103a(7) =71a(8) =661a(9) =269a(10) =329891a(11) =39916801a(12) =2834329a(13) =75024347a(14) =3790360487a(15) =46271341a(16) =1059511a(17) =1000357a(18) =123610951a(20) =117876683047