I asked the mathematician and co-editor of "Strange Attractors Poems of Love and Mathematics", Sarah Glaz for her definition of mathematical poetry and here is what she had to say:
Mathematical poetry is an umbrella term for poetry with a strong link to mathematics in either imagery, content, or structure. The mathematics involved in mathematical poetry does not have to be mathematically significant. Some poems I would call mathematical involve just arithmetic, or counting. How significant are those in the scheme the entire body of mathematical knowledge? Certain mathematical components do not make a poem mathematical, and this is expressed through the words "strong link to mathematics." For example, all formal poetry has a built in mathematical structure, but we would not call every sonnet, for example, a mathematical poem just because it has 14 lines. If the link to mathematics is in the poem's structure, there has to be something non standard, or unusual, about the use of mathematics in the poem's structure to make the poem a mathematical poem. I left, on purpose, the term "poetry" undefined because I want to include in this definition poems that have only mathematical symbols. Although my preference is for poetry that includes words, I would like the term mathematical poetry to embrace all poetic mathematical forms, even those that come to us from the depth of mathematical silence in symbol form.