A001390 Smallest multiplicative generator for quadratic residues mod prime(n).

1, 1, 4, 2, 3, 4, 2, 4, 2, 4, 7, 3, 2, 9, 2, 4, 3, 4, 4, 2, 6, 2, 3, 5, 2, 4, 2, 3, 12, 9, 9, 3, 2, 4, 4, 5, 3, 4, 2, 4, 3, 4, 2, 2, 4, 2, 4, 9, 3, 5, 7, 2, 3, 3, 9, 2, 4, 2, 7, 5, 6, 4, 7, 2, 2, 4, 5, 3, 3, 3, 9, 2, 2, 3, 4, 2, 4, 3, 2, 2, 3, 4, 5, 6, 5, 3, 2, 3, 4, 2, 3, 2, 2, 4, 5, 2, 4, 2, 4, 4, 4, 4, 3, 2, 5, 17

Offset

1,3

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

f:= proc(p) local x;
  for x from 1 do if numtheory:-order(x, p) = (p-1)/2 then return x fi od
end proc:
f(2):= 1:
seq(f(ithprime(n)), n=1..1000); # Robert Israel, Jan 14 2016

Mathematica

f[p_] := Module[{x}, For[x = 1, True, x++, If[MultiplicativeOrder[x, p] == (p - 1)/2, Return[x]]]];
f[2] = 1;
f /@ Prime[Range[100]] (* Jean-François Alcover, Jul 17 2020, after Maple *)

Crossrefs

Cf. A000040.

Sequence in context: A183993 A184403 A198120 * A180343 A332273 A225001

Adjacent sequences: A001387 A001388 A001389 * A001391 A001392 A001393

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from David W. Wilson, Aug 15 1996

Offset changed by Robert Israel, Jan 14 2016

Status

approved