What's Significant About Number 14?

The number 14, if we were to get into a time machine and go back to the first century, would be King David. Matthew just did is he took this genealogy chart and he forced it into 14 generations multiplied by three. He's clearly skipping people because we're covering 750 years from here to here. Why would he be making such a big deal that the Messiah needed to be a son of David?