我们在前面补一个(2-1)
原式=(2-1)(2+1)(2^2+1)(2^4+1)(2^8+1)……..(2^2n+1 +1)
=(2^2-1)(2^2+1)(2^4+1)(2^8+1)……..(2^2n+1 +1)
=(2^4-1)(2^4+1)(2^8+1)……..(2^2n+1 +1)
=(2^4n+2)+1
(2+1)(2^2+1)(2^4+1)(2^8+1)……..(2^2n+1 +1)
=(2-1)(2+1)(2^2+1)(2^4+1)……(2^(2n+1)+1)
=(2^2-1)(2^2+1)(2^4+1)……(2^(2n+1)+1)
=……
=(2^(2n+1)-1)(2^(2n+1)+1)
=2^(2n+2)-1
=4^(n+1)-1
最后一项显然输的还不对,应该是 (2^(2^n)+1),象一楼说的补个2-1,最后结果应该是(2^[2^(n+1)]-1)=(4^[2^n]-1)