Since "son" can mean male descendents, there is no problem here. Jeconiah (Jehoiachin) reigned about 604 B.C., so there were 14 generations from David to Jeconiah in about 400 years, or 29 years per generation.
Kwa kuwa "mwana wa" inaweza kumaanisha mzao wa kiume, hakuna shida hapa. Yekonia (Yehoyakini) alitawala karibu mwaka 604 KK, kwa hiyo kuna vizazi 14 kutoka Daudi hadi Yekonia katika kipindi cha karibu miaka 400, au miaka 29 kwa kizazi.