2的整数次幂有哪些?0和-8是吗?如果是,是2的几次幂?帮我补充下次幂的概念.

2^0 = 1 ；2^1 = 2 ,2^(-1) = 1/2 ；2^2 = 4 ,2^(-2) = 1/4 ；2^3 = 8 ,2^(-3) = 1/8 ；2^4 = 16 ,2^(-4) = 1/16 ；2^5 = 32 ,2^(-5) = 1/32 ；2^6 = 64 ,2^(-6) = 1/64 ；2^7 = 128 ,2^(-7) = 1/128 ；2^8 = 256 ,2...