C++ :

#include<iostream>
#include<iomanip>
using namespace std;

int main()
{int a[21][21];
	int n,k=1;
	cin>>n;
	for (int i=1; i<=n; i++)
		for (int j=i,x=1; x<=n-i+1; j++) a[j][x++]=k++;
	for (int i=1; i<=n; i++)
	{
		for (int j=1; j<=i; j++) cout<<setw(4)<<a[i][j];
		cout<<endl;
	}
	return 0;
}

Python :

# coding=utf-8
n=int(input())
i=n
L=[1]
print("% 4d" % 1)
while i>1:
    L2=[i+1 for i in L]
    j=L[0]+i
    L.clear()
    L.append(j)
    L.extend(L2)
    for a in L:
        print("% 4d" % a,end='')
    print()
    i-=1