#include<iostream>
#include<cstdio>
#include<vector>
#include<bitset>
#include<algorithm>
#define mod 1000000007
using namespace std;
inline int read()
{
	int n=0,f=1,ch=getchar();
	while(ch<'0'||ch>'9')
	{
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9')
	{
		n=n*10+ch-'0';
		ch=getchar();
	}
	return n*f;
}
bitset<2005>b[2005];
struct sth
{
	int d1,d2,jl;
}s[3000005];
bool bi(struct sth x,struct sth y)
{
	return x.jl<y.jl;
}
int tmp;
int pri[200005],cnt;
bool vis[200005];
int jdz(int x)
{
	if(x<0)return -x;
	return x;
}
int x[2005],y[2005]; 
int main()
{
	vis[1]=true;
	for(int i=2;i<=200000;i++)
	{
		if(!vis[i])pri[++cnt]=i;
		for(int j=1;j<=cnt&&i*pri[j]<=200000;j++)
		{
			vis[i*pri[j]]=true;
			if(i%pri[j]==0)break;
		}
	} 
	int t,n;
	t=read();
	for(int greg=1;greg<=t;greg++)
	{
		n=read();
		for(int i=1;i<=n;i++)
		{
			x[i]=read();
			y[i]=read();
		}
		tmp=0;
		for(int i=1;i<=n;i++)
		{
			for(int j=i+1;j<=n;j++)
			{
				s[++tmp].d1=i;
				s[tmp].d2=j;
				s[tmp].jl=jdz(x[i]-x[j])+jdz(y[i]-y[j]);
			}
		}
		sort(s+1,s+tmp+1,bi);
		for(int i=1;i<=n;i++)b[i].reset();
		long long ans=0;
		for(int i=1;i<=tmp;i++)
		{
			if(!vis[s[i].jl])
			{
				ans+=(b[s[i].d1]^b[s[i].d2]).count();
			} 
			b[s[i].d1][s[i].d2]=1;
			b[s[i].d2][s[i].d1]=1;
		}
		printf("%lld\n",ans);
	}
}