A217469 - OEIS

%I #24 Feb 26 2019 03:42:38

%S 2,5,4,6,4,3,6,20,22,16,6,30,10,5,9,54,42,12,8,25,52,36,14,55,6,65,16,

%T 46,72,75,4,66,82,18,20,15,6,19,42,22,102,35,18,16,112,30,29,40,20,25,

%U 64,42,18,27,22,140,20,96,36,42,48,155,39,106,54,165,12,15

%N Multiplicative order of 5 (mod 5*n + 1).

%C Least m such that 5*n + 1 divides 5^m - 1.

%H Arkadiusz Wesolowski, <a href="/A217469/b217469.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MultiplicativeOrder.html">Multiplicative Order</a>

%t Table[MultiplicativeOrder[5, 5*n + 1], {n, 68}]

%o (PARI) vector(80, n, znorder(Mod(5, 5*n+1))) \\ _Michel Marcus_, Feb 09 2015

%o (GAP) List([1..80],n->OrderMod(5,5*n+1)); # _Muniru A Asiru_, Feb 26 2019

%Y Cf. A002326, A003571, A003573.

%K nonn

%O 1,1

%A _Arkadiusz Wesolowski_, Nov 16 2012