#include<fstream.h>
int n,i,j,v[801];
int outOfBorders,mijBun,stanga,dreapta;
int merge(int a,int b, int c)
	{
	if(a+b<c) return -1;//tre sa caut la stanga
	if(a+c<b||c+b<a) return -2; // tre sa caut la dreapta
	return 1;
	}
int cauta(int directie)
	{
	int st,dr,mij;
	st=1;
	dr=n;
	while(st<=dr)
		{
		mij=(st+dr)/2;
		outOfBorders=((mij+directie>n)||(mij+directie<1));
		mijBun=merge(v[i],v[j],v[mij]);
		if(mijBun==1)
		       {
		       if(outOfBorders)
					return mij;
		       if(merge(v[i],v[j],v[mij+directie])!=1)
					return mij;
		       if(directie==1) st=mij+1;
		       else dr=mij-1;
		       }
		//else if(outOfBorders) return -1;
		else if(mijBun==-1) dr=mij-1;
		else st=mij+1;//if(mijBun==-2)
		}
	return 0;
	}
int intre(int poz)
	{
	if(poz>=stanga&&poz<=dreapta) return 1;
	return 0;
	}
int main()
{
ofstream out("nrtri.out");
int cnt=0,x,tzi;
ifstream in("nrtri.in");
in>>n;
for(i=1;i<=n;i++)
	in>>v[i];
in.close();
int aux;
for(i=1;i<n;i++)
	for(j=i+1;j<=n;j++)
		if(v[i]>v[j])
			{
			aux=v[i];
			v[i]=v[j];
			v[j]=aux;
			}
int iIntre,jIntre;
for(i=1;i<n;i++)
	for(j=i+1;j<=n;j++)
		{
		stanga=cauta(-1);
		dreapta=cauta(1);
		if(stanga!=-1)//sau dreapta ca tot aia e(adica nu a gasit nici un numar care sa mearga)
			{
			iIntre=intre(i);
			jIntre=intre(j);

			if(iIntre) cnt--;
			if(jIntre) cnt--;
			cnt+=dreapta-stanga+1;
			}
		}

out<<cnt/3<<'\n';
out.close();
return 0;
}