  If a knot has the Alexander polynomial not equal to 1, then it is linear
$n$-colorable.
  By means of such a coloring, such a knot is given an upper bound for the
minimal quandle order, i.e., the minimal order of a quandle with which the knot
is quandle colorable.
  For twist knots, we study the minimal quandle orders in detail.
