Question

有一列数,按一定的规律排列成-1,3,-9,27,-81,243,…,其中某三个相邻数的和是1701,这三个数分别是

Answer 1

-1,3,-9,27,-81,243,-729,2187,

-1*(-3)^0,-1*(-3)^1,-1*(-3)^2,-1*(-3)^3,-1*(-3)^4,-1*(-3)^5,-1*(-3)^6.,-1*(-3)^n

243-729+2187=1701

这三个数分别是243,-729,2187