这个数列为:48 24 12 6 3 3/2 3/4 3/8 3/16 3/32 .或者
3,6,12,24,48,96,192,384,768,1536,...所以 A10= 3/32 或者1536
2.A,n=S,n-S,n-1=n^2-(n-1)^2=2n+1为等差数列:1,3,5,7,9.(这个直接看的二楼的因为是正确的)
这个数列为:48 24 12 6 3 3/2 3/4 3/8 3/16 3/32 .或者
3,6,12,24,48,96,192,384,768,1536,...所以 A10= 3/32 或者1536
2.A,n=S,n-S,n-1=n^2-(n-1)^2=2n+1为等差数列:1,3,5,7,9.(这个直接看的二楼的因为是正确的)