Largest prime factor of 17^n + 1.

Terms

a(0) =2a(1) =3a(2) =29a(3) =13a(4) =41761a(5) =101a(6) =83233a(7) =22796593a(8) =184417a(9) =5653a(10) =63541a(11) =87415373a(12) =72337a(13) =2001793a(14) =100688449a(15) =238212511a(16) =52548582913a(18) =382069a(19) =20352763a(22) =6901823633