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

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...