Dev Skill DCP-210: Gabu and the Series Solution

Problem Link
Dev Skill DCP-210: Gabu and the Series Solution

#include<stdio.h>
int main()
{
    int m,n,i,j,t;
    long long int b;
    scanf("%d",&t);
    j=0;
    while(j<t)
    {
        scanf("%d",&n);
        if(n==1)
            printf("0\n");
        else if(n==2)
            printf("2\n");
        else
        {
            b=2;
            m=2;
            for(i=3;i<=n;i++)
            {
                m=m+4;
                b=b+m;
            }
            printf("%lld\n",b);
        }
        j++;
    }
    return 0;
}