[math-fun] gosper.org/matrixtower.pdf

In response to a private request, the order of evaluation of the first eight term-matrices of a Ramanujan 1/π series. The objective is to always multiply integers of comparable size. It naturally collapses to one matrix every power-of-2 terms, but is cheap to forcibly collapse occasionally, and always remains resumable, even as continued fraction terms or (feh) decimal digits are extracted by matrix multiplication on the left. (Which must imitate the fractal, "ruler function" chunking on the right to keep the integer multiplies balanced, and thus fully exploit fast arithmetic.) --rwg