“1,-4,9,-16,25,-36”和“-2,8,-18,32,-50,72”的规律

问题描述:

“1,-4,9,-16,25,-36”和“-2,8,-18,32,-50,72”的规律
快 今天就要

1,-4,9,-16,25,-36的规律是:an=(-1)^(n-1) * n^2(n=1,2,3.) ,即当项数是奇数时,该项为项数的平方;当项数是偶数时,该项为项数的平方的相反数-2,8,-18,32,-50,72的规律是:an=(-1)^n * 2 * n^2(n=1,2,3.),即当项...