Usage: 2 forms in 10 verses
Form Translated As     In Verse(s)
πεντεκαιδέκα fifteen LXX.Lev.27.7
πεντεκαίδεκα fifteen LXX.Gen.5.10LXX.Exod.27.14LXX.2Sam.9.10LXX.2Sam.19.17LXX.2Kgs.14.17LXX.2Kgs.20.6LXX.Hos.3.2
of fifteen LXX.Exod.38.14LXX.Exod.38.15

Liddell-Scott-Jones

πεντεκαίδεκα (pentekaideka) fifteen G:A

πεντεκαίδεκα, οἱ, αἱ, τά,

indeclinable, fifteen, [Refs 5th c.BC+]; οἱ π. ἄνδρες, quindecimviri sacris faciundis, [Refs 2nd c.AD+]