Josiah became the father of Jechoniah and his brothers, at the time of the exile to Babylon.

After the exile to Babylon, Jechoniah became the father of Shealtiel. Shealtiel became the father of Zerubbabel.

So all the generations from Abraham to David are fourteen generations; from David to the exile to Babylon fourteen generations; and from the carrying away to Babylon to the Christ, fourteen generations.