I had this one up the wall (giant print) at a place I worked:

https://raw.githubusercontent.com/cies/haskell-fractal/refs/... [17MB, sorry Github]

It contains the Haskell code that produced it: https://github.com/cies/haskell-fractal

Especially the `sharpen` function was interesting to come up with (I used some now-offline tool to do curve fitting for me): https://github.com/cies/haskell-fractal/blob/master/fractal....

Fun little project. :)