Largest prime < 10*a(n-1), a(1)=5.

Terms

a(0) =5a(1) =47a(2) =467a(3) =4663a(4) =46619a(5) =466183a(6) =4661819a(7) =46618183a(8) =466181801a(9) =4661818009a(10) =46618180033a(11) =466181800327