#include<iostream>
#include<math.h>
using namespace std;
int main()
{
	int i,n,x;
	float s=1,tu;
	long mau,N=1;
	cout<<"nhap n";
	cin>>n;
	cout<<"nhap x";
	cin>>x;
	for(i=1;i<=n;i++)
	{
		tu=pow(x,2*i);
		mau=2*i;
		N=N*mau*(mau-1);
		s=s+tu/(float)N;
	}
	cout<<"s="<<s;
	return 0;
}

cho e hoi doan code tren e kiem tra thay dung nhung chay ra ket qua sai a