a(n) is the smallest prime factor of n^n+1 having the form k*n+1.

Terms

a(0) =5a(1) =7a(2) =257a(3) =521a(4) =13a(5) =113a(6) =97a(7) =73a(8) =101a(9) =23a(10) =193a(11) =13417a(12) =29a(13) =31a(14) =274177a(16) =37a(17) =108301a(18) =148721a(19) =337a(21) =47a(22) =33409a(23) =239201a(24) =53a(25) =163a(26) =449a(27) =233a(28) =61a(29) =373a(30) =641a(31) =661