POJ 3006 Dirichlet's Theorem on Arithmetic Progressions
题目:给定一对互质的数a和d,序列a,a+d,a+2d,a+3d。。。包含无穷多个素数。例如:a为2,d为3时,序列为:2,5,8,11,14,17,20,23,26,29,32,35,38,41,44,47,50,53,56,59,62,65,68,71,74,77,80,83,86,89,92,95,98,...,其中素数为:2,5,11,17,23,29,41,47,53,59,71,83,