If you'll be adding a pre-population feature, I'd love to see this as one of the choices: http://en.wikipedia.org/wiki/Ulam_spiral http://en.wikipedia.org/wiki/

If you'll be adding a pre-population feature, I'd love to see this as one of the choices: http://en.wikipedia.org/wiki/Ulam_spiral http://en.wikipedia.org/wiki/Ulam_spiral