a(n) = largest prime factor of n^n + 1.

Terms

a(0) =2a(1) =5a(2) =7a(3) =257a(4) =521a(5) =97a(6) =911a(7) =673a(8) =530713a(9) =27961a(10) =58367a(11) =2227777a(12) =79301a(13) =176597a(14) =142111a(17) =33388093a(18) =870542161121a(22) =1522029233a(23) =27250359649