hdu 1249(递推)

//递推,f(i) = f(i-1) + 6 * (i-1); f[1] = 2, i>=2;
#include <cstdio>
#include <iostream>

using namespace std;

int f[10001];

int main() {
    int i;
    f[1] = 2;
    for (i=2; i<10001; ++i) f[i] = f[i-1] + 6 * (i - 1);
    int t;
    scanf ("%d", &t);
    while (t--) {
        int n;
        scanf ("%d", &n);
        printf ("%d\n", f[n]);
    }
    return 0;
}