Prime Number Spiral

Education, Mathematics

The Prime Number Spiral (a.k.a. the Ulam Spiral) is constructed as follows: Consider a rectangular grid. We start with the central point and arrange the positive integers in a spiral fashion (anticlockwise). The prime numbers are then marked. There is a tendency for the prime numbers to form diagonal lines, however far out into the spiral one goes. This is software is for exploring the Prime Number Spiral. It allows coloring of the prime numbers in various ways. Also displays a random arrangement to compare with the primes (and also displays square and triangular numbers).