The first interesting feature I call the ‘reveal shell’, which is the shell whose polygon number is the product of the proceeding prime numbers, for 3 this is 3×2×1=6.  When we put the reveal shell in place, and skirt around the inside of the shell anticlockwise, the next prime number in the sequence of prime numbers is revealed where there is no exclusion line.  Prime numbers up to the current shell (the 3 shell) are excluded, they are already in place.  For some reason the 1 always comes out, but the next number that is not occluded by an exclusion line is the next prime number.  This number is 5, Reveal Shell of the 3 shell .