Greek Grammar

Logos word/reason. tou logou of the word. tō logō to the word. ton logon the word (accusative). ō loge O word. And O logos. Dual: tō logō. toin logoin. ō logō. Plural: hoi logoi. tōn logōn. tois logois. tous logous. ō logoi.
Hē hodos the road. tēs hodou. tēi hodō. tēn hodon. ō hode. And O hodos. Dual: tō hodō. tain hodoin. ō hodō. Plural: hai hodoi. tōn hodōn. tais hodois. tas hodous. ō hodoi.
To xylon the wood. tou xylou. tō xylō. to xylon. ō xylon.
Dual: tō xylō. toin xyloin. ō xylō. Plural: ta xyla. tōn xylon. tois xylois. ta xyla. ō xyla.

These four are indeed the isosyllabic nouns having the same number of syllables in all cases. The fifth is both parisosyllabic nouns increasing by one syllable in the genitive and is itself in the three genders. Clearly, of all nouns that decline parisosyllabically, the genitive ends in -os, the dative in -i, and the accusative ends in -a.
Ho Aias Ajax. tou Aiantos. tō Aianti. ton Aianta. ō Aian. And O Aias. Dual: tō Aiante. toin Aiantoin. ō Aiante. Plural: hoi Aiantes. tōn Aiantōn. tois Aiasi. tous Aiantas. ō Aiantes.
Ho Thoas Thoas. tou Thoantos.

Nouns ending in -as pure, meaning preceded by a vowel that are masculine, disyllabic, barytone having a grave accent on the final syllable, and long-ending, decline through the -nt- meaning they take a dental consonant in their inflected forms.