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 A217852 #20 Feb 16 2025 08:33:18
%S A217852 1,6,6,9,2,14,16,4,5,42,18,29,16,22,36,39,6,44,46,30,4,27,18,48,3,42,
%T A217852 22,69,12,37,30,52,20,52,14,89,22,18,96,33,16,45,106,72,24,114,12,119,
%U A217852 30,82,42,36,10,67,136,6,5,272,42,44,36,102,156,70,54,138,166
%N A217852 Multiplicative order of 5 (mod 5*n - 1).
%C A217852 Least m such that 5*n - 1 divides 5^m - 1.
%H A217852 Arkadiusz Wesolowski, <a href="/A217852/b217852.txt">Table of n, a(n) for n = 1..10000</a>
%H A217852 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativeOrder.html">Multiplicative Order</a>
%t A217852 Table[MultiplicativeOrder[5, 5*n - 1], {n, 67}]
%o A217852 (PARI) vector(80, n, znorder(Mod(5, 5*n-1))) \\ _Michel Marcus_, Feb 09 2015
%o A217852 (GAP) List([1..70],n->OrderMod(5,5*n-1)); # _Muniru A Asiru_, Feb 25 2019
%Y A217852 Cf. A002326, A003572, A003574, A128858.
%K A217852 nonn
%O A217852 1,2
%A A217852 _Arkadiusz Wesolowski_, Nov 16 2012