#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 1000000000000000000LL

int main(){
	
	int n;
	cin>>n;
	
	vector<vector<int>> a(501);
	rep(i,n){
		int t;
		cin>>t;
		a[t].push_back(i);
	}
	long long ans = 0;
	rep(i,501){
		for(int j=i+1;j<501;j++){
			if(a[i].empty() || a[j].empty()) continue;
			long long tsum = 0;
			{
				int c = 0;
				long long psum = 0;
				rep(k,a[i].size()){
					while(a[j].size()!=c && a[j][c]<a[i][k]){
						psum += a[j][c];
						c++;
					}
					tsum += c * a[i][k] - psum;
				}
			}
			swap(i,j);
			{
				int c = 0;
				long long psum = 0;
				rep(k,a[i].size()){
					while(a[j].size()!=c && a[j][c]<a[i][k]){
						psum += a[j][c];
						c++;
					}
					tsum += c * a[i][k] - psum;
				}
			}
			swap(i,j);
			tsum *= abs(i-j);
			ans += tsum;
		}
	}
	ans *= 2;
	cout<<ans<<endl;
	return 0;
}