There is no gap in attestations for even and odd:
… þe moones [Mrg: monþes; L menses] ben euene oþir odde, for an euene mone answeriþ to an odde moneþ and an odde mone to an euene moneþ.
Oon is moder of pluralite and cause of euene and odde [L imparitatis], for if þou settest oon to an odde nombre nedes þu makest an euene nombre. — Bartholomaeus, De Proprietatibus Rerum (ME translation), ca. 1398.
In Old English there is the rare term ofertæl for an odd number, an “over number.” For tæl think of the expression all told. This was eventually replaced by borrowing from Old Norse oddatala, which is still Icelandic for an odd number. An even number is a slétt tal, ‘even, smooth’.
I was unable to determine whether Old English even numbers were efen, but I have no reason to doubt it, given the same word/concept from Scandinavia until you hit the High German of the south.
The underlying metaphor behind odd is ‘angle, point of land’, so odd numbers are pointy and angled while even ones are smooth and flat. Both Low German and Dutch use even, but odd numbers are uneven. High German goes for the vertical dimension: even numbers are gerade, ‘straight’ and ungerade.