Вычислить сумму n членов ряда 1/k^5

//---------------------------------------------------------------------------
#include <vcl>//eto tolko dlya "C++ Builder"
//dlya drugih kompilyatorov VCL ubrat
#include <iostream>
#include <math>
#pragma hdrstop
//---------------------------------------------------------------------------
#pragma argsused
using namespace std;
 
int main()
{
int k, N;
double Summa=0, an, B;
 
cout << "Vvedite N:";
cin >> N;
cout << "\n";
 
for(k = 1; k <= N; k++)
{
    an = 1/pow(k, 5);
    B *= an;
    Summa += B;
}
cout << "Summa = " << Summa << "\n";
 
system("pause");
return 0;
}

for(k = 1; k <= N; k++)
{
    an = 1/pow(k, 5);
    Summa += an;
}

pow( int x, int y );

double getSum(double n, int i)
{
    return n ? 1./pow(n, i) + getSum(n - 1, i) : 0;
}
 
int main()
{
    double N;
    int    k;
 
    cout << "Vvedite N: ";
    cin  >> N;
    
    cout << "Vvedite k: ";
    cin  >> k;
    
    cout << "Summa = " <<  getSum(N, k) << endl;
 
    return 0;
}