Gordon Shumway: The ability to leave an empty spot is identical to adding another colour.
The general formula for the number of codes with N spots and C colours is CN for regular logic; for unique logic, the formula is C!/(C-N)!, assuming there are at least as many colours as there are spots (otherwise, you wouldn't have any possible codes).
(Cacher) Si vous ne consultez que quelques uns des forums de discussions sur une base régulière, vous pouvez les ajouter à la liste de vos forums favoris en allant sur la page du Forum et en cliquant sur "Ajouter à la liste des forums favoris". (pauloaguia) (Montrer toutes les astuces)