The certificate of incorporation of any corporation may provide that at all elections of directors of the corporation, or at elections held under specified circumstances, each holder of stock or of any class or classes or of a series or series thereof shall be entitled to as many votes as shall equal the number of votes which, except for such provision as to cumulative voting, he would be entitled to cast for the election of directors with respect to his shares of stock multiplied by the number of directors to be elected by him, and that he may cast all of such votes for a single director or may distribute them among the number to be voted for, or for any two (2) or more of them as he may see fit.