Today’s exponential sum is highly symmetric:These sums are often symmetric, but not always.
For example, here’s the sum from a couple days ago:It’s not obvious from looking at the parameters whether a sum will be symmetric or not.
Maybe someone could find a prove criteria for a sum to have certain symmetries.
For more exponential sums, see this page.
There’s a link labeled details that explains what is being plotted, and each page has an animate link to show the steps in creating that image.