Prime Number Spiral v6.56 Ulam螺线工具
软件简介—SoftWare Description: Prime Number Spiral v6.56 Ulam螺线工具

Prime Number Spiral是探索研究Ulam螺线的工具软件，可绘制从1到2,147,208,022间任何数字的螺线。螺线上的数字可以圆点或方块表示。 An interesting prime number spiral was discovered in 1963 by Stanislaw M. Ulam, and is now called "the Ulam spiral". It reveals a strange property of the prime numbers. A positive integer (1, 2, 3, ... ) greater than 1 is called prime if its only divisors are 1 and itself. The first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, ... The series is infinite, since there is no largest prime number. The proof of this goes back to the ancient Greek mathematician Euclid.