（x, y）被看到仅当x与y互质
由此联想到欧拉函数
x=y是1个点，然后把正方形分成两半，一边是φ（n）
所以答案是2*∑φ（n）+1
#include<cstdio>
#include<cctype>
#define REP(i, a, b) for(int i = (a); i < (b); i++)
#define _for(i, a, b) for(int i = (a); i <= (b); i++)
using namespace std;typedef long long ll;
const int MAXN = 1123;
ll euler[MAXN];void get_euler()
{_for(i, 1, MAXN) euler[i] = i;_for(i, 2, MAXN){if(euler[i] == i)for(int j = i; j <= MAXN; j += i)euler[j] = euler[j] / i * (i - 1);euler[i] += euler[i-1]; }
}void read(ll& x)
{int f = 1; x = 0; char ch = getchar();while(!isdigit(ch)) { if(ch == '-1') f = -1; ch = getchar(); }while(isdigit(ch)) { x = x * 10 + ch - '0'; ch = getchar(); }x *= f;
}int main()
{get_euler();ll n; read(n);_for(i, 1, n){ll x; read(x);printf("%d %lld %lld\n", i, x, 2 * euler[x] + 1);}return 0;
}