The piku is a mathematical form; the word itself is a portmandeau between pi and haiku, and thereby something of its nature is revealed, just as the scifiku is a haiku using SF themes and imagery.
Essentially, it is a three-line poem, a single tercet, with three syllables in the first line, one in the second, and four in the third. These are, naturally, the first three digits of pi.
Here is my first attempt:
"A piku on Time"
Like a light,
decays each day.
You will notice that the form is best suited to a single image and/or trope, and that the careful use of sound patterns such as the assonance, consonance and pararhyme, here, can lend a greater tightness and compactness to the form. If you remember that alliteration requires the repeated initial sounds of stressed syllables rather than of words, in English prosody, the parallels between the unstressed 'l' followed by the stressed 'l' and the treatment of the initial 'd' -- in the first and third lines respectively -- add a level of pleasure and structure, a form of phonological parallelism.