One cannot (in the US) get a patent for software itself. This was settled a while ago. There needs to be more in the claims. In fact, the patent discussed here does not claim continued fractions and nobody would be in danger using them even if the patent issued as is (which is not certain, because the patent claims rather trivial modification of a classic neural network architecture, which should be brought up by the examiner as obvious).

Patents are propelling the society when they work as intended. They made XIX century and at least good chunk of XX century. Without patents, people fall back to copying each other, because it is much easier to copy than to innovate.