οὐδέ is used by the poets for but not, where Attic prose writers have ἀλλ' ου' or καὶ οὐ. Thus, ἔνθ' ἄλλοις μὲν πᾶσιν ἑήνδανεν, οὐδέ ποθ' Ἥρῃ οὐδὲ Ποσει-
ἐμαῖσι οὐδὲ σαῖσι δυσβουλίαις
οὐκ ἐμὸν τόδ' ἀλλὰ σόν
σοῦ τάδε κινδυ_νεύεις, ἀλλ' οὐκ ἐμοῦ ἀκηκοέναι
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].