Of Jeduthun: the sons of Jeduthun; Gedaliah, and Zeri, and Jeshaiah, Hashabiah, and Mattithiah, six, under the hands of their father Jeduthun, who prophesied with a harp, to give thanks and to praise the Lord. (1 Chronicles 25:3)
Only 5 names are here listed. The list in vs. 9-31 suggests that the missing name is Shimei of v. 17 (see on v. 9). The LXX includes the name Shimei, placing it 4th in the list.