練習 － Dirichlet’s Theorem on Arithmetic Progressions Posted on 2014-04-16 by Alvin Tang — Leave a reply Dirichlet’s Theorem on Arithmetic Progressions 題目：如果a和d是互質的正整數，從a開始增加d的算術序列，即a，a + d，a + 2d，a 繼續閱讀 →