FormulaGrid may stop earlier than it needs to.

[gwhitney]

Visit https://numberscope.colorado.edu/?name=OEIS+A171884&ver=0.4.0&rev=7e7b423&viz=FormulaGrid&dimensions=200&backgroundColor=000000FF&speed=1024&fillFormula=%7Bcircle%3A%0A++yellow.mix%28black%2C+1-gcd%28A%28x%29%2CA%28y%29%29%2Fsqrt%28A%28x%29A%28y%29%29%29%2C%0Amouseover%3A+%5B%0A++++%27%40%27%2C+x%2C+%27%2C+%27%2C+y%2C+%27%3A+gcd%28%27%2C+A%28x%29%2C+%27%2C+%27%2C+A%28y%29%2C+%27%29+%3D+%27%2C+gcd%28A%28x%29%2CA%28y%29%29%0A%5D%7D&inset=0.8&seq=OEIS+A171884.

The visualization stops with only a quarter of the screen filled in; the rest has been left black. But mousing over, only sequence values up to a few hundred have been used, while there are over 13 thousand entries known. So it should be able to fill in the whole screen. Thus, there seems to be some sort of early stopping bug.

However, it seems that approximately 13 thousand pixels have been filled. This coincidence suggests that the visualizer is only trying to fill in one pixel per sequence entry, whether or not it actually needs on sequence entry per pixel. Presumably, the Formula Grid visualizer should attempt to fill in every pixel, since even if one pixel requires a sequence value out of range, later pixels might end up depending on earlier sequence values and so we should see that information. (And there's really no way to tell whether a given pixel will compute successfully - trying to analyze the formulas given would be hopeless. The best you can do is just try to compute them.)