A070674 - OEIS

%I #12 Nov 18 2020 06:49:55

%S 1,1,1,1,1,1,2,1,4,1,1,1,3,9,1,1,1,7,4,1,4,1,1,1,1,3,4,9,1,1,5,1,1,1,

%T 11,13,7,5,16,1,1,25,6,1,16,1,1,1,18,1,1,9,1,7,1,9,4,1,1,1,13,5,4,1,

%U 16,1,29,1,1,11,1,25,2,7,1,5,23,55,23,1,10,1,1,25,1

%N Smallest m in range 2..n-1 such that m^9 == 1 mod n, or 1 if no such number exists.

%H Alois P. Heinz, <a href="/A070674/b070674.txt">Table of n, a(n) for n = 1..10000</a>

%p a:= proc(n) local m;

%p       for m from 2 to n-1 do

%p         if m &^ 9 mod n = 1 then return m fi

%p       od; 1

%p     end:

%p seq(a(n), n=1..100);  # _Alois P. Heinz_, Jun 29 2014

%t a[n_] := Module[{m}, For[m = 2, m <= n-1, m++, If[PowerMod[m, 9, n] == 1, Return[m]]]; 1];

%t Array[a, 100] (* _Jean-François Alcover_, Nov 18 2020 *)

%o (PARI) a(n) = {for (m=2, n-1, if (lift(Mod(m, n)^9) == 1, return (m));); return (1);} \\ _Michel Marcus_, Jun 29 2014

%Y Cf. A070667.

%K nonn

%O 1,7

%A _N. J. A. Sloane_, May 08 2002