能帮看下错哪了吗？找了半天了

x=3
n=2
t=1
jiecheng=1
for i in range(1,n+1):
    for j in range(1,i+1):
        jiecheng=jiecheng*j
    s = x**(i)
    t += (-1)**(i-1)*s/jiecheng
print(t)