There's an easy solution to your lawn chair equation: making those suckers out of pure maths. Well, maths and plastic.
That kind of abstract design nerdery is exactly what the F3 collection by Fabio Novembre is all about. Each piece's form is inspired by a mathematical form that "flows freely" although which ones specifically isn't exactly clear. The trio of seating equations were shown off at this year's Milan Design Week, where they seem to have proven sufficiently sittable. They're just designs for now, but hopefully they can cross-cancel their way to your backyard someday.
They certainly look distinctive -- and awesome -- compared to the lawn furniture you probably have. But I wouldn't want to encounter one after a beer or twelve, so maybe keep a less abstract chair around for that. [Designboom]