cp's OEIS Frontend

A070672 Smallest m in range 2..n-1 such that m^7 == 1 mod n, or 1 if no such number exists.

%I A070672 #13 Nov 20 2024 15:38:44
%S A070672 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,7,1,1,1,1,1,
%T A070672 1,1,1,1,1,1,1,1,4,1,1,1,1,1,8,1,1,1,1,1,1,1,1,7,1,1,1,1,1,1,1,1,1,1,
%U A070672 1,1,20,1,1,1,1,1,1,1,1,1,1,1,1,1,1,11,7,1,1,1,1,1
%N A070672 Smallest m in range 2..n-1 such that m^7 == 1 mod n, or 1 if no such number exists.
%H A070672 Alois P. Heinz, <a href="/A070672/b070672.txt">Table of n, a(n) for n = 1..10000</a>
%p A070672 a:= proc(n) local m;
%p A070672       for m from 2 to n-1 do
%p A070672         if m &^ 7 mod n = 1 then return m fi
%p A070672       od; 1
%p A070672     end:
%p A070672 seq(a(n), n=1..100);  # _Alois P. Heinz_, Jun 29 2014
%t A070672 a[n_] := Module[{m}, For[m = 2, m <= n-1, m++, If[PowerMod[m, 7, n] == 1, Return[m]]]; 1];
%t A070672 Table[a[n], {n, 1, 100}] (* _Jean-François Alcover_, Nov 20 2024 *)
%o A070672 (PARI) a(n) = {for (m=2, n-1, if (lift(Mod(m, n)^7) == 1, return (m));); return (1);} \\ _Michel Marcus_, Jun 29 2014
%Y A070672 Cf. A070667.
%K A070672 nonn
%O A070672 1,29
%A A070672 _N. J. A. Sloane_, May 08 2002