cp's OEIS Frontend

A070669 Smallest m in range 2..n-1 such that m^4 == 1 mod n, or 1 if no such number exists.

%I A070669 #12 Jul 20 2015 07:29:21
%S A070669 1,1,2,3,2,5,6,3,8,3,10,5,5,13,2,3,4,17,18,3,8,21,22,5,7,5,26,13,12,7,
%T A070669 30,7,10,13,6,17,6,37,5,3,9,13,42,21,8,45,46,5,48,7,4,5,23,53,12,13,
%U A070669 20,17,58,7,11,61,8,15,8,23,66,13,22,13,70,17,27,31,7
%N A070669 Smallest m in range 2..n-1 such that m^4 == 1 mod n, or 1 if no such number exists.
%H A070669 Alois P. Heinz, <a href="/A070669/b070669.txt">Table of n, a(n) for n = 1..10000</a>
%p A070669 a:= proc(n) local m;
%p A070669       for m from 2 to n-1 do
%p A070669         if m &^ 4 mod n = 1 then return m fi
%p A070669       od; 1
%p A070669     end:
%p A070669 seq(a(n), n=1..100);  # _Alois P. Heinz_, Jun 29 2014
%t A070669 a[n_] := (For[m = 2, m <= n - 1, m++, If[PowerMod[m, 4, n] == 1, Return[m]]]; 1); Table[a[n], {n, 1, 100}] (* _Jean-François Alcover_, Jul 20 2015 *)
%o A070669 (PARI) a(n) = {for (m=2, n-1, if (lift(Mod(m, n)^4) == 1, return (m));); return (1);} \\ _Michel Marcus_, Jun 29 2014
%Y A070669 Cf. A070667.
%K A070669 nonn
%O A070669 1,3
%A A070669 _N. J. A. Sloane_, May 08 2002