This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A333430 #37 Aug 29 2021 01:57:49
%S A333430 1,3,10,125,21,1379,2810,243,3125,30613,729,685633,850,183
%N A333430 a(n) is the n-th number m that divides n^m + 1 (or 0 if m does not exist).
%C A333430 a(15) > 10^19.
%C A333430 a(16) = 29623979969.
%C A333430 a(17) = 250.
%C A333430 a(19) = 13915.
%C A333430 a(15) <= 76717223012242243155874. - _Jinyuan Wang_, Mar 25 2020
%C A333430 From _Jon E. Schoenfield_, Aug 28 2021: (Start)
%C A333430 a(18) = 16983563041.
%C A333430 Next 20 terms after the first unknown term (a(15)): 29623979969, 250, 16983563041, 13915, 1143, 23426, 5608987, 2187, 75625, 25160213, 2709, 26803, a(28), 729, a(30), 2702258, 6633, 118810, 15625, 6379479. (End)
%F A333430 a(n) = A333429(n,n).
%o A333430 (PARI) a(n) = {my(c=0, m=0); while(c<n, m++; if(Mod(n, m)^m==-1, c++)); m; } \\ _Jinyuan Wang_, Mar 25 2020
%o A333430 (Python)
%o A333430 def a(n):
%o A333430 if n == 1: return 1
%o A333430 m = 0
%o A333430 for c in range(1, n+1):
%o A333430 m += 1
%o A333430 while not (pow(n, m, m) + 1)%m == 0: m += 1
%o A333430 return m
%o A333430 print([a(n) for n in range(1, 15)]) # _Michael S. Branicky_, Aug 28 2021
%Y A333430 Main diagonal of A333429.
%Y A333430 Cf. A333433.
%K A333430 nonn,hard,more
%O A333430 1,2
%A A333430 _Alois P. Heinz_, Mar 20 2020