cp's OEIS Frontend

A070668 Smallest m in range 2..n-1 such that m^3 == 1 mod n, or 1 if no such number exists.

%I A070668 #13 Jul 20 2015 07:28:52
%S A070668 1,1,1,1,1,1,2,1,4,1,1,1,3,9,1,1,1,7,7,1,4,1,1,1,1,3,10,9,1,1,5,1,1,1,
%T A070668 11,13,10,7,16,1,1,25,6,1,16,1,1,1,18,1,1,9,1,19,1,9,7,1,1,1,13,5,4,1,
%U A070668 16,1,29,1,1,11,1,25,8,47,1,45,23,55,23,1,28,1,1,25
%N A070668 Smallest m in range 2..n-1 such that m^3 == 1 mod n, or 1 if no such number exists.
%H A070668 Alois P. Heinz, <a href="/A070668/b070668.txt">Table of n, a(n) for n = 1..10000</a>
%p A070668 a:= proc(n) local m;
%p A070668       for m from 2 to n-1 do
%p A070668         if m &^ 3 mod n = 1 then return m fi
%p A070668       od; 1
%p A070668     end:
%p A070668 seq(a(n), n=1..100);  # _Alois P. Heinz_, Jun 29 2014
%t A070668 a[n_] := (For[m = 2, m <= n-1, m++, If[PowerMod[m, 3, n] == 1, Return[m]]]; 1); Table[a[n], {n, 1, 100}] (* _Jean-François Alcover_, Jul 20 2015 *)
%o A070668 (PARI) a(n) = {for (m=2, n-1, if (lift(Mod(m, n)^3) == 1, return (m));); return (1);} \\ _Michel Marcus_, Jun 29 2014
%Y A070668 Cf. A070667.
%K A070668 nonn
%O A070668 1,7
%A A070668 _N. J. A. Sloane_, May 08 2002