Найти сумму ряда с заданной точностью = 10

#define _USE_MATH_DEFINES
#include <cmath>
 
#include "stdafx.h"
#include <iostream>
 
using namespace std;
 
int factorial(int n)
{
    return (n == 1 || n == 0) ? 1 : factorial(n - 1) * n;
}
 
double Sum(double accuracy, double n)
{
    double sum = 0, current = 0, previous = 0;
 
    do {
        previous = current;
        current = 2 * factorial(n) / factorial(3 * n);
        sum += current;
    } while (abs(current - previous) > 10);
    
    return sum;
}
 
int main()
{
    double n;
    cin >> n;
    cout << Sum(10, n);
    return 0;
}

double Sum(double accuracy, [зачёркнуто] double n[/зачёркнуто])
{
    double sum = 0, current = 0;
    for (int n = 1; abs(current) > accuracy; n++)
    {
        current = 2 * factorial(n) / factorial(3 *-n);
        sum += current;
    }
    return sum;
}

#include <cmath>
#include <iostream>
 
using namespace std;
 
int factorial(int n)
{
    return (n == 1 || n == 0) ? 1 : factorial(n - 1) * n;
}
 
double Sum(double accuracy)
{
    double sum = 0, current = 0;
 
    for (int n = 1; abs(current) > accuracy; n++) {
        current = 2 * factorial(n) / factorial(3*-n);
        sum += current;
     
    }
    return sum;
}
 
int main()
{
    cout << Sum(0.01);
    return 0;
}

double sum = 0, current = accuracy+1

current = 2 * factorial(n) / factorial(3*-n);

#include <iostream.h>
#include <cmath>
 
void main ()
{
      double accuracy;
      cout << "accuracy = ";
      cin >> accuracy;
      double current = accuracy + 1;
      double sum = 0;
      double fact = 1;
      double fact3 = 1; 
      for (int n = 1; current < accuracy; n++)
      {
              fact = fact*n;
              fact3 = 3*fact3*n;
              current = 2*fact/fact3;
              sum += current;
      }
      cout << "/nSum (" << n << ") = " << sum << "/n/n";
}

      double current = accuracy + 1;
      for (int n = 1; current < accuracy; n++)

#include <iostream.h>
#include <cmath>
 
void main ()
{
    double accuracy;
    cout << "accuracy = ";
    cin >> accuracy;
    double current = accuracy + 1;
    double sum = 0;
    double fact = 1;
    double fact3 = 1; 
    for (int n = 1; current > accuracy; n++)
    {
        fact = fact*n;
        fact3 = 3*fact3*n;
        current = 2*fact/fact3;
        sum += current;
    }
    cout << "\nSum (" << n << ") = " << sum << "\n\n";
}

#include <iostream>
#include <cmath>
 
using namespace std;
 
int main()
{
    double accuracy;
    cout << "accuracy = ";
    cin >> accuracy;
    double current = accuracy + 1;
    double sum = 0;
    double fact = 1;
    double fact3 = 1;
    int n;
    for (n = 1; current > accuracy; n++)
    {
        fact = fact*n;
        fact3 = 3 * fact3*n;
        current = 2 * fact / fact3;
        sum += current;
    }
    cout << "\nSum (" << n << ") = " << sum << "\n\n";
    system("pause");
    return 0;
}

double Sum(double eps)
{
    double s,an;
    int n;
    n=1;
    an=1.0/3.0;// a1=(2*1!)/(3!)
    s=0;
    while(fabs(an)>eps)
    {
         s+=an;
         n++;
         an*=(n+1.0)/( (3.*n+1.0)*(3.*n+2.0)*(3.*n+3.0)); 
    }
    return s;
}