Geometric progression

#include <iostream>
#include <cstdlib>
#include <vector>
#include <cmath>

using namespace std;

int main()
{
    // q, n, a1, an
    // an - posledniq chlen ; sn - sumata na chlenovete; an1 - temp chlen
    double a1, n, q, an;
    double sn;
    cout << "Purvit chlen e: ";cin >> a1; cout << "Chastnoto e: "; cin >> q; cout << "Broq e "; cin >> n; cout << endl;

    int n1 = n;

    vector <double> prog = {};


    for (int i = 1; i < n+1; i++)
    {
        an = a1 * pow(q, i - 1);
        prog.push_back(an);
    }

    for (int i = 0; i <n; i++)
    {
        cout << prog[i] << " ";
    }

    //cout << "an: " << an << endl;
    //cout << "sn: " << sn << endl;
}