View Compilation Error

0_0_24360173_7438.cpp: In function 'int main()':
0_0_24360173_7438.cpp:13:34: error: expected primary-expression before '=' token
    a[i]=a[i-1]*1.0/(i+1)*(4*i-2);=
                                  ^
0_0_24360173_7438.cpp:14:4: error: expected primary-expression before 'int'
    int n;
    ^
0_0_24360173_7438.cpp:16:22: error: 'n' was not declared in this scope
    while(scanf("%d",&n)&&n>0)
                      ^