I understand this is a weird question, but I think this could be a place in which I could find the answer.
I'm trying to reprodice this image:
with a java applet. I know that this image is a grid-Fresnel zone plate" but unfortunately I don't know the reference.
I've measured the white square and this is the result (in pixels):
- the bigger dot is 8 pixel
- the second bigger is 6
- the third is 2
Now i have 8, 6, 2... How can I get the generating function of these numbers?
I hope it's clear, sorry but english is not my first language.