Gadgets with the Ulam spiral: Computation and visualization of prime numbers and more…

This interactive CDF computes the Ulam Spiral for a given start value 0,1,2,.. which can also be negative. Interesting structures of the Ulam spiral can be seen on the 4 horizontal/vertical and 4 diagonal lines in the four quadrants. Those 8 lines belong to an startpoint, which can also be offset to the center of…