Largest prime of the form n!/k!-1.

Terms

a(0) =5a(1) =23a(2) =59a(3) =719a(4) =5039a(5) =6719a(6) =181439a(7) =5039a(8) =6652799a(9) =479001599a(10) =154439a(11) =87178291199a(12) =54486431999a(18) =39070079a(19) =180503769599