Largest n-digit lucky number.

Terms

a(0) =9a(1) =99a(2) =997a(3) =9999a(4) =99987a(5) =999987a(6) =9999997a(7) =99999979a(8) =999999991a(9) =9999999997a(10) =99999999973a(11) =999999999937