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 A381924 #23 Mar 26 2025 19:15:05
%S A381924 1,2,4,3,5,12,16,6,11,28,30,9,40,21,46,13,29,60,33,7,24,13,41,88,48,
%T A381924 100,34,106,54,7,63,26,136,23,74,75,39,9,166,86,178,5,95,192,196,99,
%U A381924 105,222,113,228,29,34,120,250,256,262,67,270,46,8,47,292,153,155,312
%N A381924 Multiplicative order of n mod prime(n).
%C A381924 a(n) is the least k such that prime(n) divides n^k-1.
%H A381924 Vincenzo Librandi, <a href="/A381924/b381924.txt">Table of n, a(n) for n = 1..3500</a>
%F A381924 If n is a primitive root modulo prime(n), a(n) = prime(n) - 1.
%e A381924 a(12) = 9 because the multiplicative order of 12 mod prime(12) is 9.
%t A381924 Table[MultiplicativeOrder[n,Prime[n]],{n,65}]
%o A381924 (PARI) a(n) = znorder(Mod(n, prime(n))); \\ _Michel Marcus_, Mar 12 2025
%o A381924 (Magma) [Order(n, NthPrime(n)) : n in [1..65]]; // _Vincenzo Librandi_, Mar 25 2025
%Y A381924 Cf. A226295, A014664, A091185 (n^(-1) mod prime(n)).
%K A381924 nonn
%O A381924 1,2
%A A381924 _Giorgos Kalogeropoulos_, Mar 12 2025