The phrase "even odd" or "odd even" refers to a sequence of numbers where one is odd and the next is even or vice versa. There are many synonyms that can be used to describe this pattern, such as "alternating sequence," "mixed sequence," or "interleaved numbers." Another phrase that can be used is "parity alternation," which emphasizes the alternating nature of the sequence's odd and even numbers. In mathematical terms, this sequence can also be described as a "binary sequence" as it consists of only two types of numbers: odd and even. No matter how it's described, the even odd sequence is a unique and interesting pattern that can be seen in many contexts.