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

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, 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, 1, 1, 20, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 7, 1, 1, 1, 1, 1

Offset: 1

Author

N. J. A. Sloane, May 08 2002

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A070667.

Programs

Maple

a:= proc(n) local m;
      for m from 2 to n-1 do
        if m &^ 7 mod n = 1 then return m fi
      od; 1
    end:
seq(a(n), n=1..100);  # Alois P. Heinz, Jun 29 2014

Mathematica

a[n_] := Module[{m}, For[m = 2, m <= n-1, m++, If[PowerMod[m, 7, n] == 1, Return[m]]]; 1];
Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Nov 20 2024 *)

PARI

a(n) = {for (m=2, n-1, if (lift(Mod(m, n)^7) == 1, return (m));); return (1);} \\ Michel Marcus, Jun 29 2014