An=2.5-SIN((2n-1)/4)×(COS((2n-1)/4)+2^0.5)由SIN((2n-1)/4)得出(1/2)^0.5,(1/2)^0.5,-(1/2)^0.5,-(1/2)^0.5由COS((2n-1)/4)+2^0.5得出3/2×2^0.5,1/2×2^0.5,1/2×2^0.5,3/2×2^0.5相乘得1.5,0.5,-0.5,-1.5用2.5...