LXX Num 1:18

καὶ πᾶσαν τὴν συναγωγὴν συνήγαγον ἐν μιᾷ τοῦ μηνὸς τοῦ δευτέρου ἔτους, καὶ ἐπηξονοῦσαν κατὰ γενέσεις αὐτῶν, κατὰ πατριὰς αὐτῶν, κατὰ ἀριθμὸν ὀνομάτων αὐτῶν, ἀπὸ εἰκοσαετοῦς καὶ ἐπάνω, πᾶν ἀρσενικὸν κατὰ κεφαλὴν αὐτῶν,

and on the first day of the second month they assembled the whole congregation and recorded their ancestry by clans and families, counting one by one the names of those twenty years of age or older,