The numbers arranged in a Spiral
References
Dewdney, A. K. ``Computer Recreations: How to Pan for Primes in Numerical Gravel.'' Sci. Amer. 259, 120-123, July 1988.
Lane, C. ``Prime Spiral.'' http://www.best.com/~cdl/PrimeSpiralApplet.html.
Weisstein, E. W. ``Prime Spiral.'' Mathematica notebook PrimeSpiral.m.