Largest prime < n!-1.

Terms

a(0) =3a(1) =19a(2) =113a(3) =709a(4) =5023a(5) =40289a(6) =362867a(7) =3628789a(8) =39916787a(9) =479001587a(10) =6227020777a(11) =87178291183