each thirteen, every other thirteen or thirteen by thirteen (see Molina)
Alonso de Molina:
matlatlactli omeei. cada uno treze, o acada treze, o de treze en treze. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 53v. col. 1. Thanks to Joe Campbell for providing the transcription.