Largest prime factor of 5^n - 1.

Terms

a(0) =2a(1) =3a(2) =31a(3) =13a(4) =71a(5) =31a(6) =19531a(7) =313a(8) =829a(9) =521a(10) =12207031a(11) =601a(12) =305175781a(13) =19531a(14) =1741a(15) =11489a(16) =466344409a(17) =5167a(18) =3981071a(19) =9161a(20) =519499a(21) =12207031a(22) =332207361361a(23) =390001a(24) =9384251a(25) =305175781a(26) =31051a(27) =234750601a(29) =7621