Largest prime factor of number formed from a(n-1) with a 1 added at the end, a(1)=2.

Terms

a(0) =2a(1) =7a(2) =71a(3) =79a(4) =113a(5) =29a(6) =97a(7) =971a(8) =83a(9) =277a(10) =163a(11) =233a(12) =37a(13) =53a(14) =59a(15) =197a(16) =73a(17) =43a(18) =431a(19) =479a(20) =1597a(21) =15971a(22) =383a(23) =1277a(24) =43a(25) =431a(26) =479a(27) =1597a(28) =15971a(29) =383