#include<stdio.h>
__int64 a[2500];
int main()
{
__int64 sum,i,n;
a[1]=1;
for(i=3;i<=2500;i+=2)
a[i]+=a[i-2]+i*i;
}
while(scanf("%I64d",&n)!=EOF)
printf("%I64d\n",a[n]);
return 0;