#include<stdio.h>
#include<string.h>
int a[505];
int main()
{
int n,sum,i;
while(scanf("%d",&n)!=EOF)
for(i=n,sum=0;i>=1;i--)
sum=sum+(1+i)*i/2;
}
for(i=n-1;i>=0;i=i-2)
printf("%d\n",sum);
return 0;