摘要：
Discription Sigma function is an interesting function in Number Theory. It is denoted by the Greek letter Sigma (σ). This function actually denotes th 阅读全文
摘要：
设 g(x) = f(x) * x ，多项式 A = Σ g(i) * x^i , 多项式 B = Σ f(i) * x^i。 首先，g(x) = g(x-1) + g(x-2) + f(x-1) + 2f(x-2)，所以我们可以得到: A = x * A + x^2 * A + x * B + 2 阅读全文